RSN Amateur Radio

RSN Amateur Radio Question Pool

Question pool for the Nigeria Amateur Radio licence examinations, derived from the RSN Study Guide — Learning Content.

ClassQuestionsExam usesExam timePass mark
Novice1204060 minutes70%
General1806090 minutes70%
Advanced24080120 minutes70%

How to use this pool

  • Cover the answer key and work through each question.
  • Answer options are presented in a fixed order here; on the real exam they may be reordered.
  • Each answer includes a short explanation and a reference to the study guide section.
  • A formula sheet is provided at the end.

Licence allocation governs. Nothing in this pool grants operating privileges. You may transmit only on the bands, frequency segments, modes, bandwidths and power levels written on your own current licence.

Part 1 — Novice Question Pool

120 questions in this pool. Answers are hidden — click Show answer to reveal.

Section N1 — Rules and licensing

N001Section N1 — Rules and licensing
What is the primary purpose of the amateur radio service?
  • ATo relay business messages for payment
  • BSelf-training, intercommunication and technical investigation✓
  • CTo operate public safety networks
  • DTo provide commercial broadcasting
Show answer
B — The amateur service exists for self-training, intercommunication and technical investigation.
Reference: Study guide 1.1
N002Section N1 — Rules and licensing
Which body is the final authority for amateur radio licence conditions in Nigeria?
  • AThe local radio club
  • BThe Federal Ministry of Communications, Innovation and Digital Economy✓
  • CThe ITU
  • DThe IARU
Show answer
B — The Ministry issues licence conditions and is the final authority.
Reference: Study guide 1.2
N003Section N1 — Rules and licensing
A licence is issued to:
  • AA specific piece of equipment
  • BAn antenna
  • CA person or a club✓
  • DA frequency
Show answer
C — A licence is issued to a person or club, not to equipment.
Reference: Study guide 1.3
N004Section N1 — Rules and licensing
Which of the following is a prohibited transmission?
  • AA callsign identification
  • BCommercial advertising✓
  • CA signal report
  • DA weather observation
Show answer
B — Commercial advertising, business traffic and broadcasting are prohibited.
Reference: Study guide 1.5
N005Section N1 — Rules and licensing
What should you do first if your station is causing harmful interference?
  • AStop transmitting immediately✓
  • BIncrease power to overcome it
  • CIgnore it if the contact is important
  • DChange to a different mode
Show answer
A — Stop transmitting immediately, then investigate.
Reference: Study guide 1.6
N006Section N1 — Rules and licensing
Which station category describes a station operated from a vehicle?
  • AMobile✓
  • BFixed
  • CClub
  • DTemporary
Show answer
A — Mobile stations are operated from a vehicle.
Reference: Study guide 1.3
N041Section N1 — Rules and licensing
What does the abbreviation ITU stand for?
  • AInternational Television Union
  • BInternational Training University
  • CIndependent Transmission Unit
  • DInternational Telecommunication Union✓
Show answer
D — ITU is the International Telecommunication Union, which sets international radio regulations.
Reference: Study guide 1.2
N042Section N1 — Rules and licensing
Which document defines the amateur service internationally?
  • AThe national highway code
  • BThe equipment manual
  • CThe ITU Radio Regulations✓
  • DThe club constitution
Show answer
C — The ITU Radio Regulations define radio services including the amateur service.
Reference: Study guide 1.2
N043Section N1 — Rules and licensing
What is a club station licence?
  • AA licence issued to a club and used by its members✓
  • BA temporary permit for one day
  • CA licence for a single person only
  • DA licence for commercial use
Show answer
A — A club licence is issued to the club and used by its members.
Reference: Study guide 1.3
N044Section N1 — Rules and licensing
What must you do if you change your address?
  • AChange your callsign yourself
  • BApply for a new class of licence
  • CNothing, the licence stays valid
  • DNotify the licensing authority and amend your licence✓
Show answer
D — Licence details must be kept current with the licensing authority.
Reference: Study guide 1.3
N045Section N1 — Rules and licensing
May an unlicensed person speak on your station?
  • AOnly if they use your callsign
  • BOnly on VHF
  • CYes, at any time
  • DOnly under your direct supervision and control✓
Show answer
D — An unlicensed person may only operate under the licensee's direct supervision.
Reference: Study guide 1.3
N046Section N1 — Rules and licensing
What is the purpose of station identification?
  • ATo show the transmitter power
  • BTo record the weather
  • CTo identify the transmitting station and the operator responsible✓
  • DTo indicate the antenna type
Show answer
C — Identification shows who is transmitting and who is responsible.
Reference: Study guide 1.4
N047Section N1 — Rules and licensing
How often must you identify during a long transmission?
  • AOnce per day
  • BOnly at the end
  • COnly at the start
  • DAt the start, at the end, and at intervals during it✓
Show answer
D — Identify at the start, end and at intervals during a long transmission.
Reference: Study guide 1.4
N048Section N1 — Rules and licensing
What is a temporary station?
  • AA station operated at a location for a limited period✓
  • BA mobile station
  • CA station with low power
  • DA station without a licence
Show answer
A — A temporary station operates at a location for a limited period.
Reference: Study guide 1.3
N049Section N1 — Rules and licensing
What does harmful interference mean?
  • AInterference only from your own equipment
  • BInterference caused by weather
  • CInterference that seriously degrades, obstructs or repeatedly interrupts a radio service✓
  • DAny weak signal heard in the background
Show answer
C — Harmful interference seriously degrades or repeatedly interrupts a service.
Reference: Study guide 1.6
N050Section N1 — Rules and licensing
Who owns the radio frequency spectrum?
  • AThe highest bidder
  • BIt is a national resource managed by the state✓
  • CThe first operator to use a frequency
  • DThe equipment manufacturer
Show answer
B — The spectrum is a national resource managed on behalf of the state.
Reference: Study guide 1.2
N051Section N1 — Rules and licensing
What is the role of the National Frequency Management Council?
  • AIt issues individual amateur callsigns
  • BIt coordinates national spectrum policy✓
  • CIt runs contests
  • DIt manufactures radio equipment
Show answer
B — The Council coordinates national spectrum policy.
Reference: Study guide 1.2
N052Section N1 — Rules and licensing
What must you obtain before operating a repeater?
  • ANothing, repeaters are open
  • BA satellite licence
  • CApproval from the licensing authority✓
  • DA commercial licence
Show answer
C — Repeaters, beacons and gateways require approval.
Reference: Study guide 1.5
N118Section N1 — Rules and licensing
What is the purpose of a licence renewal?
  • ATo change your callsign
  • BTo change class
  • CTo increase power
  • DTo keep your authority to operate current✓
Show answer
D — Renewal keeps your authority to operate current.
Reference: Study guide 1.3

Section N2 — Operating practice

N007Section N2 — Operating practice
In the ITU phonetic alphabet, which word represents the letter L?
  • ALondon
  • BLincoln
  • CLima✓
  • DLima-Alfa
Show answer
C — L is Lima.
Reference: Study guide 2.1
N008Section N2 — Operating practice
What is the official ITU spelling for the letter A?
  • AAlpha
  • BAmerica
  • CAlfa✓
  • DAble
Show answer
C — The official spelling is Alfa, not Alpha.
Reference: Study guide 2.1
N009Section N2 — Operating practice
In the RST system, what does the S indicate?
  • ASelectivity
  • BStrength✓
  • CStability
  • DSpeed
Show answer
B — S is signal strength, on a scale of 1 to 9.
Reference: Study guide 2.3
N010Section N2 — Operating practice
A signal report of 59 means:
  • AReadability 5, tone 9
  • BStrength 5, tone 9
  • CReadability 9, strength 5
  • DReadability 5, strength 9✓
Show answer
D — For voice, the two digits are readability then strength.
Reference: Study guide 2.3
N011Section N2 — Operating practice
What does QSY mean?
  • AChange frequency✓
  • BYour signal is fading
  • CI am closing down
  • DWho is calling me?
Show answer
A — QSY means change frequency.
Reference: Study guide 2.4
N012Section N2 — Operating practice
Why do amateur operators use UTC?
  • AIt is required for FM only
  • BIt is the fastest time standard
  • CSo logs from different countries agree✓
  • DIt avoids the need for a logbook
Show answer
C — UTC is a common time reference so logs agree internationally.
Reference: Study guide 2.5
N013Section N2 — Operating practice
On the 2 m band, what is the typical repeater offset?
  • A±5 MHz
  • B±1.6 MHz
  • C±600 kHz✓
  • D±25 kHz
Show answer
C — The standard 2 m offset is ±600 kHz.
Reference: Study guide 2.6
N053Section N2 — Operating practice
What does a CQ call mean?
  • AA call to a specific station
  • BA general call to any station that may be listening✓
  • CA test transmission
  • DA distress call
Show answer
B — CQ is a general call inviting any station to reply.
Reference: Study guide 2.2
N054Section N2 — Operating practice
What does 73 mean in amateur radio?
  • AChange frequency
  • BSignal report follows
  • CBest regards, a friendly sign-off✓
  • DEmergency, clear the frequency
Show answer
C — 73 is a friendly sign-off meaning best regards.
Reference: Study guide 2.2
N055Section N2 — Operating practice
What does over mean?
  • AThe contact is finished
  • BI am changing frequency
  • CRepeat your last transmission
  • DI have finished transmitting and await your reply✓
Show answer
D — Over hands the transmission to the other station.
Reference: Study guide 2.2
N056Section N2 — Operating practice
What does roger mean?
  • AI am closing down
  • BPlease repeat
  • CI have received and understood your transmission✓
  • DSignal is fading
Show answer
C — Roger acknowledges that a transmission was received and understood.
Reference: Study guide 2.2
N057Section N2 — Operating practice
What is the range of the RST readability scale?
  • A0 to 10
  • B1 to 3
  • C1 to 5✓
  • D1 to 9
Show answer
C — Readability is graded 1 to 5.
Reference: Study guide 2.3
N058Section N2 — Operating practice
What is the range of the RST strength scale?
  • A0 to 9
  • B1 to 5
  • C1 to 9✓
  • D1 to 10
Show answer
C — Strength is graded 1 to 9.
Reference: Study guide 2.3
N059Section N2 — Operating practice
What does QRM mean?
  • AYour signal is fading
  • BChange frequency
  • CNatural atmospheric noise
  • DMan-made interference✓
Show answer
D — QRM is man-made interference.
Reference: Study guide 2.4
N060Section N2 — Operating practice
What does QRN mean?
  • AWho is calling me
  • BNatural or atmospheric noise✓
  • CI am closing down
  • DMan-made interference
Show answer
B — QRN is natural or atmospheric noise.
Reference: Study guide 2.4
N061Section N2 — Operating practice
What does QTH mean?
  • AMy antenna is
  • BMy name is
  • CMy power is
  • DMy location is✓
Show answer
D — QTH gives the station location.
Reference: Study guide 2.4
N062Section N2 — Operating practice
What does QSL mean?
  • AChange frequency
  • BStop transmitting
  • CAcknowledge receipt, or a confirmation card✓
  • DIncrease power
Show answer
C — QSL acknowledges receipt or refers to a confirmation card.
Reference: Study guide 2.4
N063Section N2 — Operating practice
What does QRT mean?
  • AI am stopping transmission or closing down✓
  • BI am ready to receive
  • CYour signal is fading
  • DWho is calling me
Show answer
A — QRT means stopping transmission.
Reference: Study guide 2.4
N064Section N2 — Operating practice
What does QRZ mean?
  • AChange frequency
  • BRepeat your transmission
  • CWho is calling me?✓
  • DI am closing down
Show answer
C — QRZ asks who is calling.
Reference: Study guide 2.4
N065Section N2 — Operating practice
Why should you listen before transmitting?
  • ATo avoid interrupting a contact already in progress✓
  • BTo check the battery
  • CTo measure SWR
  • DTo warm up the transmitter
Show answer
A — Listening first avoids interrupting an existing contact.
Reference: Study guide 2.2
N066Section N2 — Operating practice
What is a net control station?
  • AThe station furthest away
  • BThe station that directs the net and calls on stations to check in✓
  • CThe station with the best antenna
  • DThe station with the highest power
Show answer
B — Net control directs the net and manages check-ins.
Reference: Study guide 2.7
N119Section N2 — Operating practice
What is the purpose of a signal report?
  • ATo choose a frequency
  • BTo record the weather
  • CTo set the power level
  • DTo tell the other station how well you are receiving them✓
Show answer
D — A signal report describes reception quality.
Reference: Study guide 2.3

Section N3 — Electricity and electronics

N014Section N3 — Electricity and electronics
What is the unit of electrical resistance?
  • AVolt
  • BWatt
  • CAmpere
  • DOhm✓
Show answer
D — Resistance is measured in ohms (Ω).
Reference: Study guide 3.1
N015Section N3 — Electricity and electronics
A 12 V supply drives 0.5 A through a resistor. What is the resistance?
  • A12 Ω
  • B48 Ω
  • C24 Ω✓
  • D6 Ω
Show answer
C — R = V/I = 12/0.5 = 24 Ω.
Reference: Study guide 3.2
N016Section N3 — Electricity and electronics
A transceiver draws 20 A at 13.8 V. What power does it consume?
  • A276 W✓
  • B27.6 W
  • C138 W
  • D552 W
Show answer
A — P = V × I = 13.8 × 20 = 276 W.
Reference: Study guide 3.3
N017Section N3 — Electricity and electronics
Two 100 Ω resistors are connected in parallel. What is the total resistance?
  • A200 Ω
  • B50 Ω✓
  • C100 Ω
  • D25 Ω
Show answer
B — R = (100 × 100)/(100 + 100) = 50 Ω.
Reference: Study guide 3.4
N018Section N3 — Electricity and electronics
In a series circuit, which quantity is the same at every point?
  • ACurrent✓
  • BPower
  • CVoltage
  • DResistance
Show answer
A — Current is the same everywhere in a series circuit.
Reference: Study guide 3.4
N019Section N3 — Electricity and electronics
What is the nominal mains voltage and frequency in Nigeria?
  • A220 V at 50 Hz
  • B240 V at 60 Hz
  • C230 V at 50 Hz✓
  • D110 V at 60 Hz
Show answer
C — Nominal mains is 230 V AC at 50 Hz.
Reference: Study guide 3.5
N020Section N3 — Electricity and electronics
Which material is a good conductor?
  • AGlass
  • BCopper✓
  • CCeramic
  • DRubber
Show answer
B — Copper is a good conductor.
Reference: Study guide 3.6
N067Section N3 — Electricity and electronics
What is the unit of electric current?
  • AAmpere✓
  • BVolt
  • COhm
  • DWatt
Show answer
A — Current is measured in amperes.
Reference: Study guide 3.1
N068Section N3 — Electricity and electronics
What is the unit of electromotive force?
  • AVolt✓
  • BFarad
  • COhm
  • DAmpere
Show answer
A — Voltage or EMF is measured in volts.
Reference: Study guide 3.1
N069Section N3 — Electricity and electronics
What is the unit of power?
  • AVolt
  • BJoule
  • CAmpere
  • DWatt✓
Show answer
D — Power is measured in watts.
Reference: Study guide 3.1
N070Section N3 — Electricity and electronics
Which formula gives power from voltage and current?
  • AP = V x I✓
  • BP = V / I
  • CP = I / V
  • DP = V + I
Show answer
A — Power equals voltage multiplied by current.
Reference: Study guide 3.3
N071Section N3 — Electricity and electronics
Two 50 ohm resistors are connected in series. What is the total resistance?
  • A100 ohm✓
  • B25 ohm
  • C50 ohm
  • D200 ohm
Show answer
A — Series resistances add: 50 + 50 = 100 ohm.
Reference: Study guide 3.4
N072Section N3 — Electricity and electronics
Two 50 ohm resistors are connected in parallel. What is the total resistance?
  • A100 ohm
  • B25 ohm✓
  • C12.5 ohm
  • D50 ohm
Show answer
B — Parallel: (50 x 50)/(50 + 50) = 25 ohm.
Reference: Study guide 3.4
N073Section N3 — Electricity and electronics
A 6 V supply drives 2 A through a resistor. What is the resistance?
  • A3 ohm✓
  • B8 ohm
  • C12 ohm
  • D0.33 ohm
Show answer
A — R = V/I = 6/2 = 3 ohm.
Reference: Study guide 3.2
N074Section N3 — Electricity and electronics
A 12 V supply is connected across a 4 ohm load. What current flows?
  • A16 A
  • B48 A
  • C0.33 A
  • D3 A✓
Show answer
D — I = V/R = 12/4 = 3 A.
Reference: Study guide 3.2
N075Section N3 — Electricity and electronics
A 12 V supply drives 2 A. What power is delivered?
  • A24 W✓
  • B14 W
  • C6 W
  • D0.17 W
Show answer
A — P = V x I = 12 x 2 = 24 W.
Reference: Study guide 3.3
N076Section N3 — Electricity and electronics
What is the peak voltage of a 100 V RMS sine wave?
  • A141 V✓
  • B70.7 V
  • C200 V
  • D100 V
Show answer
A — Peak = RMS x 1.414 = 141 V.
Reference: Study guide 3.5
N077Section N3 — Electricity and electronics
What is the RMS voltage of a 100 V peak sine wave?
  • A100 V
  • B70.7 V✓
  • C141 V
  • D50 V
Show answer
B — RMS = peak x 0.707 = 70.7 V.
Reference: Study guide 3.5
N078Section N3 — Electricity and electronics
Which of these is a semiconductor?
  • AGlass
  • BCopper
  • CRubber
  • DSilicon✓
Show answer
D — Silicon is a semiconductor.
Reference: Study guide 3.6
N079Section N3 — Electricity and electronics
What does a fuse protect a circuit against?
  • AReverse polarity only
  • BExcessive current✓
  • CRadio interference
  • DExcessive voltage only
Show answer
B — A fuse opens the circuit when current is excessive.
Reference: Study guide 3.7
N080Section N3 — Electricity and electronics
What is the period of a 100 Hz signal?
  • A100 ms
  • B0.1 ms
  • C1 ms
  • D10 ms✓
Show answer
D — T = 1/f = 1/100 = 0.01 s = 10 ms.
Reference: Study guide 3.8

Section N4 — Radio theory

N021Section N4 — Radio theory
What is the wavelength at 145 MHz?
  • A2.07 m✓
  • B1.45 m
  • C20.7 m
  • D4.83 m
Show answer
A — λ = 300/145 = 2.07 m.
Reference: Study guide 3.8
N022Section N4 — Radio theory
Which frequency range defines the HF band?
  • A300 MHz to 3 GHz
  • B300 kHz to 3 MHz
  • C30 MHz to 300 MHz
  • D3 MHz to 30 MHz✓
Show answer
D — HF is 3 to 30 MHz.
Reference: Study guide 4.2
N023Section N4 — Radio theory
Which mode has the narrowest bandwidth?
  • ASSB
  • BFM voice
  • CAM
  • DCW✓
Show answer
D — CW occupies roughly 100–500 Hz.
Reference: Study guide 4.4
N024Section N4 — Radio theory
What does SSB stand for?
  • ASingle Sideband✓
  • BSimple Signal Bandwidth
  • CSynchronous Signal Broadcast
  • DStandard Signal Band
Show answer
A — SSB is Single Sideband.
Reference: Study guide 4.4
N025Section N4 — Radio theory
What is the function of a receiver's squelch control?
  • AReduces transmitter power
  • BChanges the transmit frequency
  • CMutes the receiver when no signal is present✓
  • DIncreases audio volume
Show answer
C — Squelch mutes the receiver in the absence of a signal.
Reference: Study guide 4.5
N026Section N4 — Radio theory
Which propagation mode allows HF signals to travel thousands of kilometres?
  • ALine of sight
  • BSkywave✓
  • CGround wave
  • DTropospheric scatter
Show answer
B — Skywave refraction off the ionosphere enables long-distance HF.
Reference: Study guide 4.7
N081Section N4 — Radio theory
What is the wavelength at 100 MHz?
  • A0.3 m
  • B10 m
  • C30 m
  • D3 m✓
Show answer
D — Wavelength = 300/100 = 3 m.
Reference: Study guide 3.8
N082Section N4 — Radio theory
What is the wavelength at 50 MHz?
  • A3 m
  • B6 m✓
  • C0.6 m
  • D15 m
Show answer
B — Wavelength = 300/50 = 6 m.
Reference: Study guide 3.8
N083Section N4 — Radio theory
What is the wavelength at 7 MHz?
  • A7 m
  • B42.9 m✓
  • C70 m
  • D21.4 m
Show answer
B — Wavelength = 300/7 = 42.9 m.
Reference: Study guide 3.8
N084Section N4 — Radio theory
A signal has a wavelength of 2 m. What is its frequency?
  • A300 MHz
  • B150 MHz✓
  • C600 MHz
  • D2 MHz
Show answer
B — f = 300/2 = 150 MHz.
Reference: Study guide 3.8
N085Section N4 — Radio theory
Which frequency range defines the VHF band?
  • A30 to 300 MHz✓
  • B300 to 3000 MHz
  • C300 kHz to 3 MHz
  • D3 to 30 MHz
Show answer
A — VHF is 30 to 300 MHz.
Reference: Study guide 4.2
N086Section N4 — Radio theory
Which frequency range defines the UHF band?
  • A300 to 3000 MHz✓
  • B3 to 30 GHz
  • C3 to 30 MHz
  • D30 to 300 MHz
Show answer
A — UHF is 300 to 3000 MHz.
Reference: Study guide 4.2
N087Section N4 — Radio theory
Which frequency range defines the MF band?
  • A3 to 30 MHz
  • B3 to 30 kHz
  • C30 to 300 kHz
  • D300 kHz to 3 MHz✓
Show answer
D — MF is 300 kHz to 3 MHz.
Reference: Study guide 4.2
N088Section N4 — Radio theory
What does amplitude modulation vary?
  • AThe polarisation
  • BThe frequency of the carrier
  • CThe amplitude of the carrier✓
  • DThe phase of the carrier
Show answer
C — AM varies the carrier amplitude.
Reference: Study guide 4.4
N089Section N4 — Radio theory
What does frequency modulation vary?
  • AThe power
  • BThe bandwidth only
  • CThe frequency of the carrier✓
  • DThe amplitude of the carrier
Show answer
C — FM varies the carrier frequency.
Reference: Study guide 4.4
N090Section N4 — Radio theory
How is a CW signal generated?
  • ABy changing the polarisation
  • BBy shifting the phase
  • CBy keying the carrier on and off✓
  • DBy varying the amplitude continuously
Show answer
C — CW keys the carrier on and off in Morse pattern.
Reference: Study guide 4.4
N091Section N4 — Radio theory
What is bandwidth?
  • AThe length of a transmission
  • BThe power of a signal
  • CThe height of an antenna
  • DThe range of frequencies a signal occupies✓
Show answer
D — Bandwidth is the range of frequencies occupied.
Reference: Study guide 4.4
N092Section N4 — Radio theory
What is the typical bandwidth of an SSB voice signal?
  • A2.4 to 3 kHz✓
  • B100 to 500 Hz
  • C50 Hz
  • D12.5 to 25 kHz
Show answer
A — SSB voice occupies about 2.4 to 3 kHz.
Reference: Study guide 4.4
N120Section N4 — Radio theory
What is the relationship between frequency and wavelength?
  • AWavelength is inversely proportional to frequency✓
  • BThey are directly proportional
  • CWavelength equals frequency
  • DThey are unrelated
Show answer
A — Wavelength falls as frequency rises.
Reference: Study guide 3.8

Section N5 — Antennas and feedlines

N027Section N5 — Antennas and feedlines
What is the length of a half-wave dipole for 7.1 MHz?
  • A10.1 m
  • B14.3 m
  • C40.2 m
  • D20.1 m✓
Show answer
D — Length = 143/7.1 = 20.1 m total.
Reference: Study guide 5.3
N028Section N5 — Antennas and feedlines
What is the characteristic impedance of coaxial cable used in amateur radio?
  • A50 Ω✓
  • B25 Ω
  • C300 Ω
  • D75 Ω
Show answer
A — Amateur coax is 50 Ω.
Reference: Study guide 5.4
N029Section N5 — Antennas and feedlines
What does an SWR of 1:1 indicate?
  • AA perfect match✓
  • BA short circuit
  • CTotal reflection
  • DAn open circuit
Show answer
A — 1:1 means a perfect impedance match.
Reference: Study guide 5.5
N030Section N5 — Antennas and feedlines
Which of the following causes a high SWR?
  • ACorrect antenna length
  • BA dummy load
  • CWaterlogged coaxial cable✓
  • DLow transmitter power
Show answer
C — Damaged or waterlogged coax causes mismatch.
Reference: Study guide 5.5
N031Section N5 — Antennas and feedlines
What is the purpose of a balun?
  • ATo reduce audio noise
  • BTo measure SWR
  • CTo connect a balanced load to an unbalanced feedline✓
  • DTo increase transmitter power
Show answer
C — A balun matches balanced to unbalanced.
Reference: Study guide 5.6
N032Section N5 — Antennas and feedlines
What is the purpose of radials on a vertical antenna?
  • ATo reduce wind loading
  • BTo raise the antenna
  • CTo form an artificial ground plane✓
  • DTo increase gain
Show answer
C — Radials form the ground plane.
Reference: Study guide 5.7
N033Section N5 — Antennas and feedlines
Which connector type is commonly used for HF amateur equipment?
  • APL-259 / SO-239✓
  • BUSB-C
  • CHDMI
  • DRJ45
Show answer
A — PL-259/SO-239 is the common HF connector.
Reference: Study guide 5.4
N093Section N5 — Antennas and feedlines
What is the length of a half-wave dipole for 14 MHz?
  • A20.4 m
  • B5.1 m
  • C14 m
  • D10.2 m✓
Show answer
D — Length = 143/14 = 10.2 m.
Reference: Study guide 5.3
N094Section N5 — Antennas and feedlines
What is the length of a quarter-wave vertical for 50 MHz?
  • A5 m
  • B0.72 m
  • C1.43 m✓
  • D2.86 m
Show answer
C — Length = 71.5/50 = 1.43 m.
Reference: Study guide 5.3
N095Section N5 — Antennas and feedlines
What does SWR measure?
  • AThe transmitter power
  • BHow well the antenna impedance matches the feedline✓
  • CThe signal strength
  • DThe antenna height
Show answer
B — SWR measures the quality of the impedance match.
Reference: Study guide 5.5
N096Section N5 — Antennas and feedlines
Which SWR reading indicates an excellent match?
  • AExactly 2 to 1
  • BBelow 1.5 to 1✓
  • CAbove 5 to 1
  • DAbove 3 to 1
Show answer
B — Below 1.5:1 is excellent.
Reference: Study guide 5.5
N097Section N5 — Antennas and feedlines
What is the purpose of an antenna tuner?
  • ATo transform the antenna impedance to match the transmitter✓
  • BTo filter audio
  • CTo increase transmitter power
  • DTo raise the antenna
Show answer
A — An ATU transforms impedance to match the transmitter.
Reference: Study guide 5.6
N098Section N5 — Antennas and feedlines
What is a choke used for in an antenna system?
  • ATo suppress common-mode current on the feedline✓
  • BTo increase gain
  • CTo reduce wind loading
  • DTo measure SWR
Show answer
A — A choke suppresses common-mode current.
Reference: Study guide 5.6
N099Section N5 — Antennas and feedlines
Which connector type is common on VHF test equipment?
  • ARJ45
  • BBNC✓
  • CN-type only
  • DPL-259
Show answer
B — BNC connectors are common on test equipment and VHF gear.
Reference: Study guide 5.4
N100Section N5 — Antennas and feedlines
What is a ground plane?
  • AAn artificial ground formed by radials for a vertical antenna✓
  • BA type of coax
  • CA filter
  • DA metal roof
Show answer
A — Radials form an artificial ground plane.
Reference: Study guide 5.7
N101Section N5 — Antennas and feedlines
What does polarisation describe?
  • AThe feedline impedance
  • BThe orientation of the electric field✓
  • CThe antenna height
  • DThe transmitter power
Show answer
B — Polarisation is the orientation of the electric field.
Reference: Study guide 4.3
N102Section N5 — Antennas and feedlines
What is a Yagi antenna used for?
  • AFiltering harmonics
  • BDirectional transmission and reception✓
  • COmnidirectional coverage
  • DMeasuring SWR
Show answer
B — A Yagi is a directional antenna.
Reference: Study guide 5.2
N103Section N5 — Antennas and feedlines
What is feedline loss?
  • AAttenuation of the signal as it travels along the cable✓
  • BThe cost of the cable
  • CThe antenna gain
  • DThe impedance mismatch
Show answer
A — Feedline loss is signal attenuation in the cable.
Reference: Study guide 5.4
N104Section N5 — Antennas and feedlines
What is the impedance of coaxial cable used for amateur radio?
  • A300 ohm
  • B75 ohm
  • C600 ohm
  • D50 ohm✓
Show answer
D — Amateur coax is nominally 50 ohm.
Reference: Study guide 5.4

Section N6 — Safety and interference

N034Section N6 — Safety and interference
Why must you never touch an antenna while transmitting?
  • AIt reduces output power
  • BIt detunes the antenna
  • CIt causes RF burns✓
  • DIt damages the transmitter
Show answer
C — RF burns are painful and slow to heal.
Reference: Study guide 6.2
N035Section N6 — Safety and interference
Where should a fuse be fitted in a DC feed?
  • AFuses are not needed
  • BOnly at the radio end
  • CAnywhere in the circuit
  • DClose to the battery or supply✓
Show answer
D — Fit the fuse close to the source.
Reference: Study guide 6.1
N036Section N6 — Safety and interference
Why must lead-acid batteries be vented when charging?
  • AThey release explosive hydrogen✓
  • BThey lose water
  • CThey release oxygen only
  • DThey become hot
Show answer
A — Charging releases explosive hydrogen gas.
Reference: Study guide 6.4
N037Section N6 — Safety and interference
What is the safest assumption about a power line near an antenna?
  • AAny contact is potentially fatal✓
  • BIt only matters if it is low voltage
  • CIt is insulated and safe
  • DIt can be moved during installation
Show answer
A — Assume any contact with a power line is fatal.
Reference: Study guide 6.3
N038Section N6 — Safety and interference
Which filter is used to suppress transmitter harmonics?
  • ALow-pass✓
  • BHigh-pass
  • CBand-pass
  • DNotch
Show answer
A — A low-pass filter suppresses harmonics.
Reference: Study guide 6.5
N105Section N6 — Safety and interference
What should you do before working on mains-powered equipment?
  • ADisconnect the mains supply✓
  • BIncrease the power
  • CConnect a dummy load
  • DEarth the antenna
Show answer
A — Always disconnect the mains before working on equipment.
Reference: Study guide 6.1
N106Section N6 — Safety and interference
What is an RCD used for?
  • AFiltering RF
  • BProtection against earth leakage and electric shock✓
  • CMeasuring SWR
  • DIncreasing power
Show answer
B — An RCD trips on earth leakage to protect people.
Reference: Study guide 6.1
N107Section N6 — Safety and interference
Why is RF exposure a health concern?
  • AIt causes static electricity
  • BIt damages antennas
  • CRF energy heats body tissue✓
  • DIt reduces signal strength
Show answer
C — RF energy heats body tissue.
Reference: Study guide 6.2
N108Section N6 — Safety and interference
Which measure reduces RF exposure?
  • ALowering the antenna
  • BUsing a higher gain antenna
  • CRaising power
  • DLowering power and increasing distance from the antenna✓
Show answer
D — Lower power and greater distance reduce exposure.
Reference: Study guide 6.2
N109Section N6 — Safety and interference
What should you do to antennas before a storm?
  • ANothing
  • BIncrease power
  • CRaise them higher
  • DLower and disconnect them✓
Show answer
D — Lower and disconnect antennas before storms.
Reference: Study guide 6.3
N110Section N6 — Safety and interference
What is the first step when interference is reported to you?
  • AStop transmitting and investigate✓
  • BIgnore it
  • CIncrease power
  • DChange your callsign
Show answer
A — Stop transmitting first, then investigate.
Reference: Study guide 6.5
N111Section N6 — Safety and interference
Which filter suppresses transmitter harmonics?
  • ABand-pass
  • BNotch
  • CHigh-pass
  • DLow-pass✓
Show answer
D — A low-pass filter suppresses harmonics.
Reference: Study guide 6.5
N112Section N6 — Safety and interference
What is a ferrite choke used for?
  • AMeasuring power
  • BIncreasing antenna gain
  • CSuppressing interference on cables✓
  • DCharging batteries
Show answer
C — Ferrite chokes suppress interference on cables.
Reference: Study guide 6.5
N113Section N6 — Safety and interference
What should you never do with a fuse?
  • ALabel it clearly
  • BBypass it or fit one of a larger rating✓
  • CReplace it with the same rating
  • DFit it close to the supply
Show answer
B — Never bypass a fuse or fit a larger one.
Reference: Study guide 6.1

Section N7 — Digital awareness

N039Section N7 — Digital awareness
What does APRS stand for?
  • AAutomatic Packet Reporting System✓
  • BAutomatic Power Reduction System
  • CAdvanced Packet Relay System
  • DAmateur Position Radio Service
Show answer
A — APRS is the Automatic Packet Reporting System.
Reference: Study guide 7
N040Section N7 — Digital awareness
When using a digital hotspot, you must:
  • AAlways identify with your callsign✓
  • BTurn off your radio
  • CUse encryption
  • DUse a special callsign
Show answer
A — Always identify with your callsign, even on a hotspot.
Reference: Study guide 7
N114Section N7 — Digital awareness
What does DMR stand for?
  • ADual Mode Radio
  • BDigital Mobile Radio✓
  • CDigital Message Relay
  • DDirect Mode Repeater
Show answer
B — DMR is Digital Mobile Radio.
Reference: Study guide 7
N115Section N7 — Digital awareness
What does D-STAR stand for?
  • ADirect Satellite Transmission And Relay
  • BDigital Station Tracking And Reporting
  • CDigital Smart Technologies for Amateur Radio✓
  • DDigital Signal Transmission And Reception
Show answer
C — D-STAR is Digital Smart Technologies for Amateur Radio.
Reference: Study guide 7
N116Section N7 — Digital awareness
What is a hotspot in amateur radio?
  • AA small device linking a local digital radio to the internet✓
  • BA high-power repeater
  • CA frequency band
  • DA type of antenna
Show answer
A — A hotspot links a digital radio to a network.
Reference: Study guide 7
N117Section N7 — Digital awareness
What must you always do when using digital systems?
  • AIncrease power
  • BIdentify with your callsign✓
  • CUse encryption
  • DDisable your callsign
Show answer
B — Always identify with your callsign, including on hotspots.
Reference: Study guide 7

Part 2 — General Question Pool

180 questions in this pool. Answers are hidden — click Show answer to reveal.

Section G1 — Rules and operating procedures

G001Section G1 — Rules and operating procedures
What is a band plan?
  • AA voluntary agreement dividing a band by mode and bandwidth✓
  • BA list of licensed operators
  • CA schedule of contests
  • DA legal frequency allocation
Show answer
A — Band plans are voluntary agreements to avoid clashes.
Reference: Study guide 8.1
G002Section G1 — Rules and operating procedures
In a typical HF band plan, where is CW found?
  • AIn the middle
  • BAt the bottom of the band✓
  • COnly in the 10 m band
  • DAt the top of the band
Show answer
B — CW occupies the bottom of each band.
Reference: Study guide 8.1
G003Section G1 — Rules and operating procedures
What does a secondary allocation mean?
  • AAmateurs have exclusive use
  • BAmateurs must not interfere with primary users and must accept interference✓
  • CAmateurs may use any power
  • DAmateurs have equal rights with primary users
Show answer
B — On a secondary allocation, amateurs must protect primary users.
Reference: Study guide 8.2
G004Section G1 — Rules and operating procedures
What is split-frequency operation?
  • AOperating two stations at once
  • BUsing two antennas
  • CSplitting the power between two bands
  • DTransmitting and receiving on different frequencies✓
Show answer
D — Split operation uses different transmit and receive frequencies.
Reference: Study guide 8.3
G005Section G1 — Rules and operating procedures
What is third-party traffic?
  • AA message to three stations
  • BA relayed contest exchange
  • CA message passed on behalf of a non-amateur✓
  • DA message sent three times
Show answer
C — Third-party traffic is passed for a non-amateur.
Reference: Study guide 8.3
G006Section G1 — Rules and operating procedures
What should you do if an emergency net is active on a frequency?
  • AContinue your contact
  • BIncrease power
  • CMove to the same frequency
  • DStop transmitting and stand by✓
Show answer
D — Emergency traffic has priority; stop and stand by.
Reference: Study guide 8.4
G007Section G1 — Rules and operating procedures
Which language should be used for emergency messages?
  • AQ-codes
  • BPlain language✓
  • CEncrypted text
  • DMorse code only
Show answer
B — Use plain language for emergency messages.
Reference: Study guide 8.4
G061Section G1 — Rules and operating procedures
What is the purpose of a band plan?
  • ATo divide a band by mode and bandwidth so activities do not clash✓
  • BTo list licensed operators
  • CTo set power limits
  • DTo allocate frequencies legally
Show answer
A — Band plans divide bands by mode and bandwidth to avoid clashes.
Reference: Study guide 8.1
G062Section G1 — Rules and operating procedures
Where in a band plan are narrow digital modes usually found?
  • AIn the middle of the SSB segment
  • BJust above the CW segment✓
  • CBelow the CW segment
  • DAt the very top of the band
Show answer
B — Narrow digital modes sit just above CW.
Reference: Study guide 8.1
G063Section G1 — Rules and operating procedures
What does a primary allocation mean for amateurs?
  • AAmateurs have exclusive use
  • BAmateurs may not transmit
  • CAmateurs must accept interference
  • DAmateurs have equal rights with other primary services and are protected✓
Show answer
D — A primary allocation gives equal rights and protection.
Reference: Study guide 8.2
G064Section G1 — Rules and operating procedures
What must you do on a secondary allocation if a primary user appears?
  • AIncrease power
  • BMove frequency or stop transmitting✓
  • CChange mode
  • DContinue as normal
Show answer
B — On a secondary allocation you must not interfere and must give way.
Reference: Study guide 8.2
G065Section G1 — Rules and operating procedures
What is a pileup?
  • AMany stations calling one DX station at once✓
  • BA band plan segment
  • CA type of antenna
  • DA group of repeaters
Show answer
A — A pileup is many stations calling one DX station.
Reference: Study guide 8.3
G066Section G1 — Rules and operating procedures
When should you call a DX station in a pileup?
  • AAt any time
  • BOnly at the end
  • COnly on the hour
  • DOnly when the DX station invites calls✓
Show answer
D — Call only when the DX station invites.
Reference: Study guide 8.3
G067Section G1 — Rules and operating procedures
What is a contest exchange usually made up of?
  • AA callsign only
  • BA weather report
  • CA signal report plus a serial number or zone✓
  • DA full name and address
Show answer
C — Contest exchanges are short: report plus serial or zone.
Reference: Study guide 8.3
G068Section G1 — Rules and operating procedures
What is the precedence field in an emergency message?
  • AThe date and time
  • BA code showing how urgent the message is✓
  • CThe sender's callsign
  • DThe message number
Show answer
B — Precedence shows the urgency of the message.
Reference: Study guide 8.4
G069Section G1 — Rules and operating procedures
Why should emergency messages use plain language?
  • ASo they are understood by everyone handling them✓
  • BTo save time only
  • CTo hide the content
  • DBecause codes are illegal
Show answer
A — Plain language ensures the message is understood.
Reference: Study guide 8.4
G070Section G1 — Rules and operating procedures
What is a third-party message?
  • AA message to three stations
  • BA message passed on behalf of a non-amateur✓
  • CA relayed contest exchange
  • DA message sent three times
Show answer
B — Third-party traffic is passed for a non-amateur.
Reference: Study guide 8.3
G071Section G1 — Rules and operating procedures
What is split-frequency operation used for?
  • AWorking a pileup where the DX station listens on a different frequency✓
  • BUsing two antennas
  • CSplitting power between bands
  • DOperating two stations
Show answer
A — Split operation separates transmit and receive frequencies.
Reference: Study guide 8.3
G072Section G1 — Rules and operating procedures
What should you do if you hear an emergency net in progress?
  • AChange frequency and continue
  • BContinue your contact
  • CStop transmitting and stand by✓
  • DJoin the net
Show answer
C — Emergency traffic has priority; stop and stand by.
Reference: Study guide 8.4
G073Section G1 — Rules and operating procedures
What is the purpose of a station log?
  • ATo tune the antenna
  • BTo increase power
  • CTo measure SWR
  • DTo record contacts as evidence of compliant operation✓
Show answer
D — A log records contacts and demonstrates compliance.
Reference: Study guide 8.3
G074Section G1 — Rules and operating procedures
What is a beacon?
  • AA type of antenna
  • BAn automatically transmitting station used to study propagation✓
  • CA satellite
  • DA repeater
Show answer
B — Beacons transmit automatically to aid propagation study.
Reference: Study guide 8.3
G165Section G1 — Rules and operating procedures
What is the purpose of a repeater offset?
  • ATo reduce noise
  • BTo increase power
  • CTo separate the input and output frequencies so the repeater can retransmit✓
  • DTo change the mode
Show answer
C — The offset separates input and output frequencies.
Reference: Study guide 8.1
G173Section G1 — Rules and operating procedures
What is the purpose of a clear-frequency check?
  • ATo test the antenna
  • BTo check the battery
  • CTo confirm the frequency is not already in use before transmitting✓
  • DTo measure SWR
Show answer
C — A clear-frequency check confirms the frequency is free.
Reference: Study guide 8.1
G178Section G1 — Rules and operating procedures
What is the purpose of a calling frequency?
  • AAn agreed frequency where stations may call CQ✓
  • BA repeater output
  • CA frequency reserved for emergencies
  • DA beacon frequency
Show answer
A — Calling frequencies are agreed for making initial calls.
Reference: Study guide 8.1

Section G2 — HF propagation

G008Section G2 — HF propagation
Which ionospheric layer causes daytime HF absorption?
  • AE layer
  • BD layer✓
  • CF2 layer
  • DF1 layer
Show answer
B — The D layer absorbs HF and exists only in daylight.
Reference: Study guide 9.1
G009Section G2 — HF propagation
Which layer is the main refracting layer for long-distance HF?
  • AD layer
  • BE layer
  • CTroposphere
  • DF2 layer✓
Show answer
D — The F2 layer supports long-distance HF.
Reference: Study guide 9.1
G010Section G2 — HF propagation
What does MUF stand for?
  • AMean Upper Frequency
  • BMaximum Usable Frequency✓
  • CMulti-hop Usable Frequency
  • DMinimum Usable Frequency
Show answer
B — MUF is the Maximum Usable Frequency.
Reference: Study guide 9.2
G011Section G2 — HF propagation
What is the skip zone?
  • AThe area beyond the MUF
  • BThe area between ground wave range and the first skywave hop✓
  • CThe area above the ionosphere
  • DThe area reached by the ground wave
Show answer
B — The skip zone is the gap between ground wave and first hop.
Reference: Study guide 9.2
G012Section G2 — HF propagation
What is NVIS used for?
  • ALong-distance DX
  • BMicrowave links
  • CShort-range HF communication✓
  • DSatellite communication
Show answer
C — NVIS uses high-angle radiation for short-range HF.
Reference: Study guide 9.2
G013Section G2 — HF propagation
What does a high solar flux index indicate?
  • AIncreased noise only
  • BNo effect on propagation
  • CPoor HF conditions
  • DHigher MUF and better HF conditions✓
Show answer
D — Higher SFI means more ionisation and better HF.
Reference: Study guide 9.3
G014Section G2 — HF propagation
What is greyline propagation?
  • APropagation along the dawn/dusk terminator✓
  • BPropagation during a solar flare
  • CPropagation through fog
  • DPropagation at midnight only
Show answer
A — Greyline is enhanced propagation along the terminator.
Reference: Study guide 9.2
G015Section G2 — HF propagation
What causes sporadic E?
  • APatches of intense ionisation in the E layer✓
  • BSolar flares
  • CTemperature inversions
  • DMeteor showers only
Show answer
A — Sporadic E is intense, unpredictable E-layer ionisation.
Reference: Study guide 9.2
G075Section G2 — HF propagation
Which ionospheric layer is present only during daylight?
  • AF1 layer
  • BF2 layer
  • CD layer✓
  • DE layer
Show answer
C — The D layer exists only in daylight.
Reference: Study guide 9.1
G076Section G2 — HF propagation
What is the approximate height of the F2 layer?
  • A150 to 220 km
  • B60 to 90 km
  • C90 to 150 km
  • D220 to 400 km✓
Show answer
D — The F2 layer lies roughly 220 to 400 km up.
Reference: Study guide 9.1
G077Section G2 — HF propagation
What is the critical frequency?
  • AThe lowest usable frequency
  • BThe maximum power frequency
  • CThe frequency of optimum traffic
  • DThe highest frequency reflected vertically by a layer✓
Show answer
D — Critical frequency is the highest vertically reflected frequency.
Reference: Study guide 9.2
G078Section G2 — HF propagation
What is the frequency of optimum traffic?
  • AAbout 85 percent of the MUF✓
  • BThe MUF itself
  • CThe LUF
  • DThe critical frequency
Show answer
A — FOT is about 85 percent of the MUF.
Reference: Study guide 9.2
G079Section G2 — HF propagation
What is multi-hop propagation?
  • AA signal refracted several times between the ionosphere and the ground✓
  • BA signal reflected by buildings
  • CA signal through a repeater
  • DA signal along the ground
Show answer
A — Multi-hop signals refract repeatedly between ionosphere and ground.
Reference: Study guide 9.2
G080Section G2 — HF propagation
What is the skip distance?
  • AThe length of the antenna
  • BThe maximum range of a ground wave
  • CThe distance to the ionosphere
  • DThe minimum distance reached by a skywave hop✓
Show answer
D — Skip distance is the minimum distance of a skywave hop.
Reference: Study guide 9.2
G081Section G2 — HF propagation
What is fading?
  • AVariation in signal strength from multipath or changing ionisation✓
  • BA change in modulation
  • CA change in frequency
  • DA change in antenna gain
Show answer
A — Fading is signal strength variation.
Reference: Study guide 9.2
G082Section G2 — HF propagation
How long is the solar cycle?
  • AAbout 1 year
  • BAbout 5 years
  • CAbout 11 years✓
  • DAbout 25 years
Show answer
C — The solar cycle is about 11 years.
Reference: Study guide 9.3
G083Section G2 — HF propagation
What does a high geomagnetic activity index indicate?
  • ABetter VHF openings
  • BImproved HF conditions
  • CDisturbed ionosphere and degraded HF conditions✓
  • DHigher MUF
Show answer
C — High geomagnetic activity degrades HF.
Reference: Study guide 9.3
G084Section G2 — HF propagation
What can a solar flare cause?
  • AA sudden ionospheric disturbance that blacks out HF✓
  • BLower noise
  • CImproved HF conditions
  • DHigher antenna gain
Show answer
A — Solar flares can black out HF for minutes to hours.
Reference: Study guide 9.3
G085Section G2 — HF propagation
What is tropospheric ducting?
  • ATemperature inversions trapping signals and carrying them long distances✓
  • BReflection from the ionosphere
  • CReflection from the moon
  • DReflection from meteor trails
Show answer
A — Tropospheric ducting traps VHF/UHF signals in inversions.
Reference: Study guide 9.4
G086Section G2 — HF propagation
What is meteor scatter used for?
  • ABrief VHF reflections from meteor trails✓
  • BLong-distance HF
  • CSatellite communication
  • DMicrowave links
Show answer
A — Meteor scatter uses brief reflections from meteor trails.
Reference: Study guide 9.4
G087Section G2 — HF propagation
What is Earth-Moon-Earth communication?
  • AUsing satellites
  • BUsing repeaters
  • CUsing the ionosphere
  • DBouncing signals off the moon✓
Show answer
D — EME bounces signals off the moon.
Reference: Study guide 9.4
G088Section G2 — HF propagation
What is auroral scatter?
  • AReflection from buildings
  • BReflection from auroral ionisation producing distorted signals✓
  • CReflection from rain
  • DReflection from the ground
Show answer
B — Auroral scatter produces distorted-sounding signals.
Reference: Study guide 9.4
G166Section G2 — HF propagation
What is ground wave propagation?
  • AA signal through a repeater
  • BA signal refracted by the ionosphere
  • CA signal following the earth's surface, useful on LF and MF✓
  • DA signal reflected by buildings
Show answer
C — Ground wave follows the earth's surface.
Reference: Study guide 9.1
G174Section G2 — HF propagation
What is the approximate height of the E layer?
  • A60 to 90 km
  • B90 to 150 km✓
  • C150 to 220 km
  • D220 to 400 km
Show answer
B — The E layer lies roughly 90 to 150 km up.
Reference: Study guide 9.1

Section G3 — Electronics and circuits

G016Section G3 — Electronics and circuits
What is the formula for capacitive reactance?
  • AX_C = 2πfL
  • BX_C = 1/(2πfC)✓
  • CX_C = 1/(2πfL)
  • DX_C = 2πfC
Show answer
B — X_C = 1/(2πfC).
Reference: Study guide 10.1
G017Section G3 — Electronics and circuits
How does a capacitor's reactance change as frequency rises?
  • AIt stays constant
  • BIt becomes infinite
  • CIt falls✓
  • DIt rises
Show answer
C — Capacitive reactance falls as frequency rises.
Reference: Study guide 10.1
G018Section G3 — Electronics and circuits
What is the resonant frequency of a 100 µH inductor and a 100 pF capacitor?
  • A159 kHz
  • B15.9 MHz
  • C1.59 MHz✓
  • D3.18 MHz
Show answer
C — f = 1/(2π√(LC)) ≈ 1.59 MHz.
Reference: Study guide 10.3
G019Section G3 — Electronics and circuits
At resonance in a series circuit, the impedance is:
  • AMinimum✓
  • BZero reactance but maximum resistance
  • CInfinite
  • DMaximum
Show answer
A — A series resonant circuit has minimum impedance.
Reference: Study guide 10.3
G020Section G3 — Electronics and circuits
What does a high Q factor indicate?
  • ALow loss
  • BHigh power
  • CA narrow bandwidth✓
  • DA wide bandwidth
Show answer
C — High Q means narrow bandwidth and sharp tuning.
Reference: Study guide 10.4
G021Section G3 — Electronics and circuits
Which filter would you use to remove a specific interfering carrier?
  • ABand-pass
  • BLow-pass
  • CHigh-pass
  • DNotch✓
Show answer
D — A notch filter blocks a narrow range.
Reference: Study guide 10.5
G022Section G3 — Electronics and circuits
Which semiconductor device conducts in one direction only?
  • ADiode✓
  • BCapacitor
  • CInductor
  • DResistor
Show answer
A — A diode conducts one way.
Reference: Study guide 10.6
G023Section G3 — Electronics and circuits
What is the function of a rectifier?
  • AConverts AC to pulsating DC✓
  • BAmplifies RF
  • CConverts DC to AC
  • DFilters audio
Show answer
A — A rectifier converts AC to pulsating DC.
Reference: Study guide 10.7
G089Section G3 — Electronics and circuits
What is the formula for inductive reactance?
  • AX_L = 2 pi f C
  • BX_L = 1/(2 pi f L)
  • CX_L = 1/(2 pi f C)
  • DX_L = 2 pi f L✓
Show answer
D — Inductive reactance is X_L = 2 pi f L.
Reference: Study guide 10.1
G090Section G3 — Electronics and circuits
How does an inductor's reactance change as frequency rises?
  • AIt becomes zero
  • BIt rises✓
  • CIt stays constant
  • DIt falls
Show answer
B — Inductive reactance rises with frequency.
Reference: Study guide 10.1
G091Section G3 — Electronics and circuits
What is the impedance of a circuit with R = 30 ohm and net reactance 40 ohm?
  • A10 ohm
  • B1200 ohm
  • C70 ohm
  • D50 ohm✓
Show answer
D — Z = sqrt(30^2 + 40^2) = 50 ohm.
Reference: Study guide 10.2
G092Section G3 — Electronics and circuits
At resonance, what is the relationship between X_L and X_C?
  • AX_C is much larger
  • BBoth are zero
  • CX_L is much larger
  • DThey are equal and cancel✓
Show answer
D — At resonance X_L equals X_C and they cancel.
Reference: Study guide 10.2
G093Section G3 — Electronics and circuits
What is the resonant frequency of a 25 uH inductor and a 100 pF capacitor?
  • A31.8 MHz
  • B3.18 MHz✓
  • C1.59 MHz
  • D318 kHz
Show answer
B — f = 1/(2 pi sqrt(LC)) = 3.18 MHz.
Reference: Study guide 10.3
G094Section G3 — Electronics and circuits
What is the resonant frequency of a 10 uH inductor and a 100 pF capacitor?
  • A1.59 MHz
  • B503 kHz
  • C5.03 MHz✓
  • D50.3 MHz
Show answer
C — f = 1/(2 pi sqrt(LC)) = 5.03 MHz.
Reference: Study guide 10.3
G095Section G3 — Electronics and circuits
What is the impedance of a parallel resonant circuit at resonance?
  • AZero
  • BEqual to the reactance
  • CMinimum
  • DMaximum✓
Show answer
D — A parallel resonant circuit has maximum impedance at resonance.
Reference: Study guide 10.3
G096Section G3 — Electronics and circuits
What does a low Q factor indicate?
  • AHigh loss only
  • BHigh power
  • CA narrow bandwidth
  • DA wide bandwidth✓
Show answer
D — Low Q means a wide bandwidth.
Reference: Study guide 10.4
G097Section G3 — Electronics and circuits
Which filter passes frequencies above a cutoff?
  • AHigh-pass✓
  • BLow-pass
  • CBand-pass
  • DNotch
Show answer
A — A high-pass filter passes frequencies above cutoff.
Reference: Study guide 10.5
G098Section G3 — Electronics and circuits
Which filter passes a range of frequencies?
  • AHigh-pass
  • BNotch
  • CLow-pass
  • DBand-pass✓
Show answer
D — A band-pass filter passes a range.
Reference: Study guide 10.5
G099Section G3 — Electronics and circuits
What is the function of a zener diode?
  • AFiltering audio
  • BRegulating voltage by conducting in reverse at a set voltage✓
  • CRectifying AC
  • DAmplifying RF
Show answer
B — A zener diode regulates voltage.
Reference: Study guide 10.6
G100Section G3 — Electronics and circuits
Which device is voltage-controlled?
  • AResistor
  • BBipolar transistor
  • CField-effect transistor✓
  • DDiode
Show answer
C — A FET is voltage-controlled.
Reference: Study guide 10.6
G101Section G3 — Electronics and circuits
What does a smoothing capacitor do in a power supply?
  • AReduces ripple in the rectified output✓
  • BRegulates current
  • CIncreases voltage
  • DFilters RF
Show answer
A — A smoothing capacitor reduces ripple.
Reference: Study guide 10.7
G102Section G3 — Electronics and circuits
What is the dB gain for a power increase from 5 W to 50 W?
  • A10 dB✓
  • B100 dB
  • C20 dB
  • D5 dB
Show answer
A — x10 power is +10 dB.
Reference: Study guide 10.8
G167Section G3 — Electronics and circuits
What is the reactance of a 1 uF capacitor at 50 Hz?
  • AAbout 3.18 ohm
  • BAbout 31.8 kohm
  • CAbout 3183 ohm✓
  • DAbout 318 ohm
Show answer
C — X_C = 1/(2 pi f C) = 3183 ohm.
Reference: Study guide 10.1
G175Section G3 — Electronics and circuits
What is the purpose of a voltage regulator?
  • ATo rectify AC
  • BTo hold the output voltage steady✓
  • CTo filter RF
  • DTo increase current
Show answer
B — A regulator holds the output voltage steady.
Reference: Study guide 10.7
G179Section G3 — Electronics and circuits
What is the purpose of a transformer in a power supply?
  • ATo smooth ripple
  • BTo regulate voltage
  • CTo rectify AC
  • DTo step mains voltage up or down✓
Show answer
D — A transformer changes AC voltage level.
Reference: Study guide 10.7

Section G4 — Transmitters and receivers

G024Section G4 — Transmitters and receivers
What is the function of the oscillator in a transmitter?
  • AFilters harmonics
  • BGenerates the carrier✓
  • CAmplifies the signal
  • DMatches the antenna
Show answer
B — The oscillator generates the carrier.
Reference: Study guide 11.1
G025Section G4 — Transmitters and receivers
What is transmitter duty cycle?
  • AThe frequency stability
  • BThe efficiency
  • CThe fraction of time at full power✓
  • DThe output power
Show answer
C — Duty cycle is the fraction of time at full power.
Reference: Study guide 11.2
G026Section G4 — Transmitters and receivers
Which mode has the highest duty cycle?
  • AAM
  • BSSB
  • CCW
  • DFT8✓
Show answer
D — FT8 and FM have high duty cycles; CW and SSB are low.
Reference: Study guide 11.2
G027Section G4 — Transmitters and receivers
In a superheterodyne receiver, what is the mixer's function?
  • AAmplifies audio
  • BFilters harmonics
  • CCombines the signal with the local oscillator to produce the IF✓
  • DControls volume
Show answer
C — The mixer produces the intermediate frequency.
Reference: Study guide 11.3
G028Section G4 — Transmitters and receivers
Why is a fixed intermediate frequency used?
  • AFiltering is easier at a fixed frequency✓
  • BIt increases power
  • CIt is cheaper
  • DIt reduces noise
Show answer
A — A fixed IF makes filtering practical.
Reference: Study guide 11.3
G029Section G4 — Transmitters and receivers
What does receiver selectivity describe?
  • AAbility to reject nearby strong signals✓
  • BAudio quality
  • CFrequency stability
  • DAbility to detect weak signals
Show answer
A — Selectivity is the ability to reject adjacent signals.
Reference: Study guide 11.3
G030Section G4 — Transmitters and receivers
What does AGC do?
  • AReduces SWR
  • BIncreases transmitter power
  • CChanges frequency
  • DHolds receiver output steady as signal strength varies✓
Show answer
D — AGC is automatic gain control.
Reference: Study guide 11.3
G031Section G4 — Transmitters and receivers
What is the main advantage of an SDR?
  • AFlexible filtering and waterfall displays✓
  • BHigher power
  • CLower cost only
  • DNo antenna needed
Show answer
A — SDR offers flexible DSP-based filtering and displays.
Reference: Study guide 11.4
G103Section G4 — Transmitters and receivers
What is the function of a buffer stage in a transmitter?
  • ATo match the antenna
  • BTo amplify audio
  • CTo isolate the oscillator from later stages✓
  • DTo filter harmonics
Show answer
C — A buffer isolates the oscillator.
Reference: Study guide 11.1
G104Section G4 — Transmitters and receivers
What is the function of the driver stage?
  • ATo filter harmonics
  • BTo raise the signal to the level the final stage needs✓
  • CTo demodulate
  • DTo generate the carrier
Show answer
B — The driver raises the signal for the final stage.
Reference: Study guide 11.1
G105Section G4 — Transmitters and receivers
What is transmitter efficiency?
  • AOutput power divided by frequency
  • BRF output divided by DC input✓
  • CDC input divided by RF output
  • DPower divided by SWR
Show answer
B — Efficiency is RF output over DC input.
Reference: Study guide 11.2
G106Section G4 — Transmitters and receivers
A transmitter produces 100 W RF from 200 W DC input. What is the efficiency?
  • A50 percent✓
  • B75 percent
  • C25 percent
  • D100 percent
Show answer
A — Efficiency = 100/200 = 50 percent.
Reference: Study guide 11.2
G107Section G4 — Transmitters and receivers
What are harmonics?
  • AUnwanted multiples of the operating frequency✓
  • BAudio frequencies
  • CPower supply ripple
  • DWanted sidebands
Show answer
A — Harmonics are unwanted multiples of the operating frequency.
Reference: Study guide 11.2
G108Section G4 — Transmitters and receivers
What are spurious emissions?
  • AHarmonics only
  • BUnwanted emissions outside the necessary bandwidth✓
  • CAudio distortion
  • DWanted sidebands
Show answer
B — Spurious emissions are unwanted emissions outside the necessary bandwidth.
Reference: Study guide 11.2
G109Section G4 — Transmitters and receivers
What is the function of the RF amplifier in a receiver?
  • ATo generate the carrier
  • BTo drive the speaker
  • CTo amplify the incoming signal before the mixer✓
  • DTo demodulate
Show answer
C — The RF amplifier boosts the incoming signal.
Reference: Study guide 11.3
G110Section G4 — Transmitters and receivers
What is the image frequency in a superheterodyne receiver?
  • AThe audio frequency
  • BThe local oscillator frequency
  • CThe wanted signal frequency
  • DAn unwanted response at f_LO plus or minus 2 f_IF✓
Show answer
D — The image is at f_LO +/- 2 f_IF.
Reference: Study guide 11.3
G111Section G4 — Transmitters and receivers
What does receiver sensitivity describe?
  • AThe ability to detect weak signals✓
  • BThe ability to reject strong signals
  • CThe frequency stability
  • DThe audio quality
Show answer
A — Sensitivity is the ability to detect weak signals.
Reference: Study guide 11.3
G112Section G4 — Transmitters and receivers
What does receiver dynamic range describe?
  • AThe range from the noise floor to the onset of overload✓
  • BThe tuning range
  • CThe audio range
  • DThe power range
Show answer
A — Dynamic range spans noise floor to overload.
Reference: Study guide 11.3
G113Section G4 — Transmitters and receivers
What is intermodulation?
  • ASpurious signals produced by mixing of strong signals✓
  • BA filter response
  • CA power supply effect
  • DA type of modulation
Show answer
A — Intermodulation produces spurious signals from strong signals.
Reference: Study guide 11.3
G114Section G4 — Transmitters and receivers
What does a noise blanker reduce?
  • AAdjacent channel signals
  • BAudio distortion
  • CImpulsive noise such as ignition interference✓
  • DContinuous background noise
Show answer
C — A noise blanker reduces impulsive noise.
Reference: Study guide 11.3
G115Section G4 — Transmitters and receivers
What does an ADC do in an SDR?
  • AConverts analogue signals to digital✓
  • BAmplifies RF
  • CFilters audio
  • DConverts digital to analogue
Show answer
A — An ADC converts analogue to digital.
Reference: Study guide 11.4
G116Section G4 — Transmitters and receivers
What is a disadvantage of SDR?
  • AIt cannot demodulate SSB
  • BIt cannot filter
  • CIt has no waterfall display
  • DIt can be affected by ADC overload and clock noise✓
Show answer
D — SDR can suffer ADC overload and clock noise.
Reference: Study guide 11.4
G168Section G4 — Transmitters and receivers
What is the purpose of a low-pass filter after the power amplifier?
  • ATo reduce audio noise
  • BTo increase power
  • CTo match impedance
  • DTo remove harmonics before the signal reaches the antenna✓
Show answer
D — The low-pass filter removes harmonics.
Reference: Study guide 11.1
G176Section G4 — Transmitters and receivers
What is frequency stability?
  • AThe modulation depth
  • BThe output power
  • CHow little the transmitted frequency drifts✓
  • DThe bandwidth
Show answer
C — Frequency stability is freedom from drift.
Reference: Study guide 11.2

Section G5 — Antennas and transmission lines

G032Section G5 — Antennas and transmission lines
What determines the characteristic impedance of coaxial cable?
  • AIts length
  • BThe frequency
  • CIts geometry and dielectric✓
  • DThe transmitter power
Show answer
C — Geometry and dielectric set the impedance, not length.
Reference: Study guide 12.1
G033Section G5 — Antennas and transmission lines
What is velocity factor?
  • AThe power handling capacity
  • BThe cable's impedance
  • CThe attenuation per metre
  • DThe speed of the signal in the cable as a fraction of the speed of light✓
Show answer
D — Velocity factor is signal speed relative to c.
Reference: Study guide 12.1
G034Section G5 — Antennas and transmission lines
What causes common-mode current?
  • ALow transmitter power
  • BCurrent flowing on the outside of the coax shield✓
  • CCurrent in the centre conductor
  • DHigh SWR only
Show answer
B — Common-mode current flows on the shield's outer surface.
Reference: Study guide 12.1
G035Section G5 — Antennas and transmission lines
How do you cure common-mode current?
  • AFit a choke or balun at the feedpoint✓
  • BShorten the coax
  • CIncrease power
  • DChange the mode
Show answer
A — A choke or balun suppresses common-mode current.
Reference: Study guide 12.1
G036Section G5 — Antennas and transmission lines
What is the gain of a half-wave dipole?
  • A10 dBi
  • BAbout 2.15 dBi✓
  • C5 dBi
  • D0 dBi
Show answer
B — A dipole has about 2.15 dBi gain.
Reference: Study guide 12.3
G037Section G5 — Antennas and transmission lines
What is the relationship between dBd and dBi?
  • AThey are identical
  • BdBi = dBd + 2.15✓
  • CdBi = dBd × 2.15
  • DdBi = dBd − 2.15
Show answer
B — dBi = dBd + 2.15.
Reference: Study guide 12.3
G038Section G5 — Antennas and transmission lines
Which antenna is omnidirectional?
  • AVertical✓
  • BPhased array
  • CLog periodic
  • DYagi
Show answer
A — A vertical radiates omnidirectionally.
Reference: Study guide 12.4
G039Section G5 — Antennas and transmission lines
What is the feed point impedance of a resonant half-wave dipole?
  • A50 Ω
  • B600 Ω
  • C73 Ω✓
  • D300 Ω
Show answer
C — A resonant dipole presents about 73 Ω.
Reference: Study guide 12.4
G040Section G5 — Antennas and transmission lines
What is the purpose of a counterpoise?
  • AFilters harmonics
  • BIncreases gain
  • CProvides the missing half of an end-fed antenna✓
  • DReduces wind loading
Show answer
C — A counterpoise supplies the missing half of the antenna.
Reference: Study guide 12.5
G117Section G5 — Antennas and transmission lines
What is electrical length?
  • AThe antenna height
  • BPhysical length divided by frequency
  • CThe feedline impedance
  • DPhysical length multiplied by the velocity factor✓
Show answer
D — Electrical length is physical length times velocity factor.
Reference: Study guide 12.1
G118Section G5 — Antennas and transmission lines
What is the electrical length of 20 m of coax with a velocity factor of 0.66?
  • A20 m
  • B13.2 m✓
  • C1.32 m
  • D30.3 m
Show answer
B — Electrical length = 20 x 0.66 = 13.2 m.
Reference: Study guide 12.1
G119Section G5 — Antennas and transmission lines
What does common-mode current cause?
  • AIncreased gain
  • BBetter matching
  • CFeedline radiation, TVI and unpredictable SWR✓
  • DLower loss
Show answer
C — Common-mode current causes radiation and interference.
Reference: Study guide 12.1
G120Section G5 — Antennas and transmission lines
Which network uses one inductor and one capacitor?
  • AStub
  • BT network
  • CL network✓
  • DPi network
Show answer
C — An L network uses one L and one C.
Reference: Study guide 12.2
G121Section G5 — Antennas and transmission lines
What is a stub used for?
  • AMeasuring SWR
  • BIncreasing power
  • CFiltering audio
  • DCancelling reactance in a transmission line✓
Show answer
D — A stub cancels reactance.
Reference: Study guide 12.2
G122Section G5 — Antennas and transmission lines
What is antenna gain?
  • AThe feed point impedance
  • BThe increase in signal in a preferred direction✓
  • CThe total radiated power
  • DThe bandwidth
Show answer
B — Gain is increased signal in a preferred direction.
Reference: Study guide 12.3
G123Section G5 — Antennas and transmission lines
What is beamwidth?
  • AThe gain in dB
  • BThe feedline loss
  • CThe angular width of the main radiation lobe✓
  • DThe antenna length
Show answer
C — Beamwidth is the angular width of the main lobe.
Reference: Study guide 12.3
G124Section G5 — Antennas and transmission lines
What is the feed point impedance of a folded dipole?
  • AAbout 73 ohm
  • BAbout 300 ohm✓
  • CAbout 600 ohm
  • DAbout 50 ohm
Show answer
B — A folded dipole presents about 300 ohm.
Reference: Study guide 12.4
G125Section G5 — Antennas and transmission lines
Which antenna needs only one high support?
  • AVertical
  • BInverted V✓
  • CLog periodic
  • DYagi
Show answer
B — An inverted V needs only one high support.
Reference: Study guide 12.4
G126Section G5 — Antennas and transmission lines
What is a trap dipole used for?
  • AIncreasing gain
  • BMeasuring SWR
  • CReducing noise
  • DMulti-band operation using tuned traps✓
Show answer
D — Traps allow multi-band operation.
Reference: Study guide 12.4
G127Section G5 — Antennas and transmission lines
What is a magnetic loop antenna good for?
  • AMaximum gain
  • BLong-distance DX only
  • CMicrowave work
  • DRestricted space where a full-size antenna will not fit✓
Show answer
D — Magnetic loops suit restricted spaces.
Reference: Study guide 12.4
G128Section G5 — Antennas and transmission lines
What is a counterpoise?
  • AA filter
  • BA conductor providing the missing half of an end-fed antenna✓
  • CA type of balun
  • DA ground rod
Show answer
B — A counterpoise supplies the missing half of the antenna.
Reference: Study guide 12.5
G129Section G5 — Antennas and transmission lines
Why is bonding all equipment to one earth point important?
  • AIt reduces SWR
  • BIt increases power
  • CIt improves gain
  • DIt prevents RF circulating in the shack✓
Show answer
D — Bonding prevents RF circulating in the shack.
Reference: Study guide 12.5
G130Section G5 — Antennas and transmission lines
What is the gain in dBi of an antenna rated at 5 dBd?
  • A5 dBi
  • B2.85 dBi
  • C7.15 dBi✓
  • D10 dBi
Show answer
C — dBi = dBd + 2.15 = 7.15 dBi.
Reference: Study guide 12.3
G169Section G5 — Antennas and transmission lines
What is the purpose of a balun at the antenna feed point?
  • ATo match a balanced antenna to an unbalanced feedline✓
  • BTo reduce wind loading
  • CTo increase gain
  • DTo measure SWR
Show answer
A — A balun matches balanced to unbalanced.
Reference: Study guide 12.2
G180Section G5 — Antennas and transmission lines
What is the purpose of a radial field?
  • ATo increase gain on HF
  • BTo measure SWR
  • CTo improve the efficiency of a vertical antenna✓
  • DTo filter harmonics
Show answer
C — Radials improve vertical antenna efficiency.
Reference: Study guide 12.5

Section G6 — Digital modes and satellite operation

G041Section G6 — Digital modes and satellite operation
What is the slot length for FT8?
  • A60 seconds
  • B15 seconds✓
  • C30 seconds
  • D7.5 seconds
Show answer
B — FT8 uses 15-second slots.
Reference: Study guide 13.1
G042Section G6 — Digital modes and satellite operation
Why does FT8 need accurate time?
  • ATo change frequency
  • BTo reduce power
  • CTo log the contact
  • DTo decode the signal correctly✓
Show answer
D — FT8 requires time accuracy within about one second.
Reference: Study guide 13.1
G043Section G6 — Digital modes and satellite operation
What is the bandwidth of an FT8 signal?
  • AAbout 500 Hz
  • BAbout 25 kHz
  • CAbout 50 Hz✓
  • DAbout 2.4 kHz
Show answer
C — FT8 signals are about 50 Hz wide.
Reference: Study guide 13.1
G044Section G6 — Digital modes and satellite operation
What does CAT control allow?
  • AAutomatic antenna tuning
  • BThe computer to set frequency, mode and PTT✓
  • CRemote power control
  • DAutomatic logging only
Show answer
B — CAT lets the computer control the transceiver.
Reference: Study guide 13.2
G045Section G6 — Digital modes and satellite operation
What is Doppler shift?
  • AA change in apparent frequency due to relative motion✓
  • BA change in signal strength
  • CA change in modulation
  • DA change in antenna gain
Show answer
A — Doppler shift is an apparent frequency change from motion.
Reference: Study guide 13.3
G046Section G6 — Digital modes and satellite operation
On the 70 cm band, how large can satellite Doppler shift be?
  • A±100 kHz
  • B±10 kHz✓
  • C±100 Hz
  • D±1 kHz
Show answer
B — Doppler shift on 70 cm can reach about ±10 kHz.
Reference: Study guide 13.3
G047Section G6 — Digital modes and satellite operation
What is full-duplex satellite operation?
  • ATransmitting and receiving simultaneously✓
  • BOperating on two bands at once
  • CUsing two antennas
  • DUsing two satellites
Show answer
A — Full duplex means hearing your own downlink while transmitting.
Reference: Study guide 13.3
G131Section G6 — Digital modes and satellite operation
What is the slot length for FT4?
  • A60 seconds
  • B7.5 seconds✓
  • C15 seconds
  • D30 seconds
Show answer
B — FT4 uses 7.5-second slots.
Reference: Study guide 13.1
G132Section G6 — Digital modes and satellite operation
What is JS8Call built on?
  • ADMR
  • BFT8 technology for keyboard-to-keyboard messaging✓
  • CPacket radio
  • DRTTY
Show answer
B — JS8Call uses FT8 technology for messaging.
Reference: Study guide 13.1
G133Section G6 — Digital modes and satellite operation
What is RTTY?
  • AAn antenna type
  • BA satellite mode
  • CA digital voice mode
  • DA classic FSK teleprinter mode✓
Show answer
D — RTTY is a classic FSK teleprinter mode.
Reference: Study guide 13.1
G134Section G6 — Digital modes and satellite operation
What is Winlink used for?
  • AAntenna modelling
  • BDigital voice
  • CSending email over radio✓
  • DSatellite tracking
Show answer
C — Winlink provides email over radio.
Reference: Study guide 13.1
G135Section G6 — Digital modes and satellite operation
What does a sound card interface do?
  • AMeasures SWR
  • BCharges the battery
  • CTunes the antenna
  • DConnects the radio audio to the computer✓
Show answer
D — A sound card interface links radio audio to the computer.
Reference: Study guide 13.2
G136Section G6 — Digital modes and satellite operation
What should the ALC reading be when setting digital audio levels?
  • AIgnored
  • BAt half scale
  • CAt maximum
  • DBarely moving✓
Show answer
D — ALC should barely move to avoid overdriving.
Reference: Study guide 13.2
G137Section G6 — Digital modes and satellite operation
What is the uplink of a satellite?
  • AThe telemetry frequency
  • BThe beacon frequency
  • CThe frequency you receive
  • DThe frequency you transmit to the satellite✓
Show answer
D — The uplink is what you transmit to the satellite.
Reference: Study guide 13.3
G138Section G6 — Digital modes and satellite operation
What is the downlink of a satellite?
  • AThe frequency you receive from the satellite✓
  • BThe power supply
  • CThe control frequency
  • DThe frequency you transmit
Show answer
A — The downlink is what you receive from the satellite.
Reference: Study guide 13.3
G139Section G6 — Digital modes and satellite operation
On the 2 m band, how large can satellite Doppler shift be?
  • AAbout 300 Hz
  • BAbout 3 kHz✓
  • CAbout 300 kHz
  • DAbout 30 kHz
Show answer
B — Doppler shift on 2 m is about 3 kHz.
Reference: Study guide 13.3
G140Section G6 — Digital modes and satellite operation
Why is full-duplex operation useful for satellites?
  • AYou can hear your own downlink and adjust as the pass progresses✓
  • BIt increases satellite range
  • CIt removes Doppler shift
  • DIt doubles your power
Show answer
A — Full duplex lets you hear your own downlink.
Reference: Study guide 13.3
G141Section G6 — Digital modes and satellite operation
What is a satellite footprint?
  • AThe uplink frequency
  • BThe orbital period
  • CThe area of the earth covered by the satellite's signal✓
  • DThe satellite's physical size
Show answer
C — The footprint is the covered area on the ground.
Reference: Study guide 13.3
G142Section G6 — Digital modes and satellite operation
Why should you respect a satellite's power limits?
  • ASatellites are shared resources with limited power budgets✓
  • BIt is only a legal formality
  • CIt reduces your SWR
  • DIt improves your antenna gain
Show answer
A — Satellites are shared and power-limited.
Reference: Study guide 13.3
G170Section G6 — Digital modes and satellite operation
What is packet radio used for?
  • AAntenna modelling
  • BDigital voice
  • CSatellite tracking
  • DAX.25 data for messaging and bulletin boards✓
Show answer
D — Packet radio carries AX.25 data.
Reference: Study guide 13.1
G177Section G6 — Digital modes and satellite operation
What is the purpose of CAT control?
  • ATo let the computer set frequency, mode and PTT✓
  • BTo tune the antenna
  • CTo charge the battery
  • DTo measure SWR
Show answer
A — CAT lets the computer control the transceiver.
Reference: Study guide 13.2

Section G7 — Safety and EMC

G048Section G7 — Safety and EMC
Which frequency range is absorbed most by the human body?
  • A1–3 GHz
  • B30–300 MHz✓
  • CAbove 10 GHz
  • D1–10 MHz
Show answer
B — The body absorbs most between 30 and 300 MHz.
Reference: Study guide 14.1
G049Section G7 — Safety and EMC
How does RF exposure change with distance?
  • AIt falls linearly with distance
  • BIt is constant
  • CIt rises with distance
  • DIt falls with the square of distance✓
Show answer
D — Exposure falls with the square of distance.
Reference: Study guide 14.1
G050Section G7 — Safety and EMC
What is electromagnetic compatibility?
  • AUsing the correct power level
  • BMatching antenna impedance
  • CEquipment working without interfering with or being interfered with✓
  • DReducing RF exposure
Show answer
C — EMC is mutual non-interference.
Reference: Study guide 14.2
G051Section G7 — Safety and EMC
Which is a common source of RF interference in a modern home?
  • AIncandescent lamps
  • BCoaxial cable
  • CLead-acid batteries
  • DSwitch-mode power supplies✓
Show answer
D — Switch-mode supplies generate RF noise.
Reference: Study guide 14.2
G052Section G7 — Safety and EMC
What is the first step when investigating interference to a neighbour?
  • AAccuse them of faulty equipment
  • BChange your callsign
  • CIncrease your power
  • DIdentify the source before drawing conclusions✓
Show answer
D — Identify the source first.
Reference: Study guide 14.2
G053Section G7 — Safety and EMC
Which fire extinguisher type is suitable for electrical fires?
  • AWet chemical
  • BDry powder or CO₂✓
  • CFoam
  • DWater
Show answer
B — Use dry powder or CO₂ for electrical fires.
Reference: Study guide 14.3
G143Section G7 — Safety and EMC
What is the main factor determining RF absorption in the body?
  • AFeedline type
  • BCallsign
  • CFrequency✓
  • DAntenna height
Show answer
C — Frequency determines how much RF the body absorbs.
Reference: Study guide 14.1
G144Section G7 — Safety and EMC
How does exposure change if you double the distance from an antenna?
  • AIt falls to one quarter✓
  • BIt stays the same
  • CIt doubles
  • DIt halves
Show answer
A — Exposure falls with the square of distance.
Reference: Study guide 14.1
G145Section G7 — Safety and EMC
What is duty cycle?
  • AThe frequency stability
  • BThe efficiency
  • CThe output power
  • DThe fraction of time a transmitter is at full power✓
Show answer
D — Duty cycle is the fraction of time at full power.
Reference: Study guide 14.1
G146Section G7 — Safety and EMC
Which mode has a low duty cycle?
  • AFT8
  • BCW✓
  • CFM
  • DRTTY
Show answer
B — CW has a low duty cycle.
Reference: Study guide 14.1
G147Section G7 — Safety and EMC
Which is a common source of RF interference in a home?
  • AIncandescent lamps
  • BSwitch-mode power supplies✓
  • CCoaxial cable
  • DLead-acid batteries
Show answer
B — Switch-mode supplies generate RF noise.
Reference: Study guide 14.2
G148Section G7 — Safety and EMC
What is a low-pass filter used for at the transmitter?
  • AFiltering audio
  • BIncreasing power
  • CReducing SWR
  • DSuppressing harmonics✓
Show answer
D — A low-pass filter suppresses harmonics.
Reference: Study guide 14.2
G149Section G7 — Safety and EMC
What is the purpose of a lightning arrestor?
  • ATo divert surge energy to earth✓
  • BTo increase gain
  • CTo reduce SWR
  • DTo filter audio
Show answer
A — A lightning arrestor diverts surge energy to earth.
Reference: Study guide 14.3
G150Section G7 — Safety and EMC
Which fire extinguisher type suits electrical fires?
  • AWater
  • BWet chemical
  • CFoam
  • DDry powder or CO2✓
Show answer
D — Use dry powder or CO2 for electrical fires.
Reference: Study guide 14.3
G151Section G7 — Safety and EMC
Why should fuses and breakers be labelled?
  • ASo they can be identified and reset safely✓
  • BTo reduce noise
  • CTo increase power
  • DTo improve SWR
Show answer
A — Labelling aids safe identification and resetting.
Reference: Study guide 14.3
G152Section G7 — Safety and EMC
What should you never do with a safety device?
  • ABypass it✓
  • BTest it
  • CReplace it with the same rating
  • DLabel it
Show answer
A — Never bypass a safety device.
Reference: Study guide 14.3
G171Section G7 — Safety and EMC
What is the purpose of an antenna exclusion zone?
  • ATo keep people out of areas where RF exposure exceeds limits✓
  • BTo improve gain
  • CTo protect the antenna from damage
  • DTo reduce wind loading
Show answer
A — Exclusion zones keep people out of high-exposure areas.
Reference: Study guide 14.1

Section G8 — Calculations

G054Section G8 — Calculations
Convert 100 W to dBm.
  • A50 dBm✓
  • B100 dBm
  • C20 dBm
  • D30 dBm
Show answer
A — 10 log₁₀(100/0.001) = 50 dBm.
Reference: Study guide 10.8
G055Section G8 — Calculations
A power increase from 10 W to 40 W represents a gain of:
  • A10 dB
  • B12 dB
  • C3 dB
  • D6 dB✓
Show answer
D — ×4 power = +6 dB.
Reference: Study guide 10.8
G056Section G8 — Calculations
What is the length of a quarter-wave vertical for 146 MHz?
  • A0.98 m
  • B2.05 m
  • C1.46 m
  • D0.49 m✓
Show answer
D — 71.5/146 = 0.49 m.
Reference: Study guide 5.3
G057Section G8 — Calculations
What is the wavelength at 28.5 MHz?
  • A0.105 m
  • B1.05 m
  • C105 m
  • D10.5 m✓
Show answer
D — λ = 300/28.5 = 10.5 m.
Reference: Study guide 3.8
G058Section G8 — Calculations
A 50 Ω load is fed with 100 W. What is the RMS voltage across it?
  • A70.7 V✓
  • B100 V
  • C141 V
  • D50 V
Show answer
A — V = √(PR) = √(100 × 50) = 70.7 V.
Reference: Study guide 3.3
G059Section G8 — Calculations
What is the peak voltage of a 230 V RMS sine wave?
  • A325 V✓
  • B230 V
  • C163 V
  • D460 V
Show answer
A — V_pk = 230 × 1.414 = 325 V.
Reference: Study guide 3.5
G060Section G8 — Calculations
An SWR of 2:1 reflects approximately what percentage of forward power?
  • A25%
  • B2%
  • C50%
  • D11%✓
Show answer
D — 2:1 SWR reflects about 11% of power.
Reference: Study guide 5.5
G153Section G8 — Calculations
Convert 10 W to dBm.
  • A10 dBm
  • B30 dBm
  • C20 dBm
  • D40 dBm✓
Show answer
D — 10 log10(10/0.001) = 40 dBm.
Reference: Study guide 10.8
G154Section G8 — Calculations
Convert 1 W to dBm.
  • A20 dBm
  • B0 dBm
  • C10 dBm
  • D30 dBm✓
Show answer
D — 10 log10(1/0.001) = 30 dBm.
Reference: Study guide 10.8
G155Section G8 — Calculations
Convert 50 W to dBm.
  • A50 dBm
  • B57 dBm
  • C37 dBm
  • D47 dBm✓
Show answer
D — 10 log10(50/0.001) = 47 dBm.
Reference: Study guide 10.8
G156Section G8 — Calculations
A power increase from 10 W to 20 W represents what gain?
  • A6 dB
  • B10 dB
  • C3 dB✓
  • D2 dB
Show answer
C — x2 power is +3 dB.
Reference: Study guide 10.8
G157Section G8 — Calculations
A power reduction from 100 W to 10 W represents what loss?
  • A10 dB✓
  • B20 dB
  • C100 dB
  • D3 dB
Show answer
A — x0.1 power is -10 dB.
Reference: Study guide 10.8
G158Section G8 — Calculations
What is the length of a half-wave dipole for 21 MHz?
  • A6.8 m✓
  • B3.4 m
  • C13.6 m
  • D21 m
Show answer
A — Length = 143/21 = 6.8 m.
Reference: Study guide 5.3
G159Section G8 — Calculations
What is the length of a quarter-wave vertical for 28 MHz?
  • A1.28 m
  • B5.1 m
  • C2.8 m
  • D2.55 m✓
Show answer
D — Length = 71.5/28 = 2.55 m.
Reference: Study guide 5.3
G160Section G8 — Calculations
What is the wavelength at 21 MHz?
  • A21 m
  • B14.3 m✓
  • C28.6 m
  • D7.1 m
Show answer
B — Wavelength = 300/21 = 14.3 m.
Reference: Study guide 3.8
G161Section G8 — Calculations
A 50 ohm load is fed with 25 W. What is the RMS voltage across it?
  • A35.4 V✓
  • B50 V
  • C25 V
  • D70.7 V
Show answer
A — V = sqrt(PR) = sqrt(25 x 50) = 35.4 V.
Reference: Study guide 3.3
G162Section G8 — Calculations
A 50 ohm load is fed with 400 W. What is the RMS voltage across it?
  • A100 V
  • B141 V✓
  • C200 V
  • D400 V
Show answer
B — V = sqrt(400 x 50) = 141 V.
Reference: Study guide 3.3
G163Section G8 — Calculations
An SWR of 3 to 1 reflects approximately what percentage of forward power?
  • A3 percent
  • B50 percent
  • C25 percent✓
  • D11 percent
Show answer
C — 3:1 SWR reflects about 25 percent.
Reference: Study guide 5.5
G164Section G8 — Calculations
What is the period of a 1 MHz signal?
  • A1 second
  • B1 microsecond✓
  • C1 nanosecond
  • D1 millisecond
Show answer
B — T = 1/1,000,000 = 1 microsecond.
Reference: Study guide 3.8
G172Section G8 — Calculations
What is the wavelength at 3.5 MHz?
  • A35 m
  • B857 m
  • C8.57 m
  • D85.7 m✓
Show answer
D — Wavelength = 300/3.5 = 85.7 m.
Reference: Study guide 3.8

Part 3 — Advanced Question Pool

240 questions in this pool. Answers are hidden — click Show answer to reveal.

Section A1 — Advanced RF theory

A001Section A1 — Advanced RF theory
How is impedance expressed in complex form?
  • AZ = R + jX✓
  • BZ = R × X
  • CZ = R − X
  • DZ = R/X
Show answer
A — Z = R + jX, where X is reactance.
Reference: Study guide 15.1
A002Section A1 — Advanced RF theory
A positive reactance indicates:
  • AAn inductive load✓
  • BA short circuit
  • CA resistive load
  • DA capacitive load
Show answer
A — Positive X is inductive.
Reference: Study guide 15.1
A003Section A1 — Advanced RF theory
What is at the centre of a Smith chart?
  • ATotal reflection
  • BA short circuit
  • CA perfect match✓
  • DAn open circuit
Show answer
C — The centre is Γ = 0, a perfect match.
Reference: Study guide 15.1
A004Section A1 — Advanced RF theory
What is at the left edge of a Smith chart?
  • AA perfect match
  • BAn open circuit
  • CInfinite impedance
  • DA short circuit✓
Show answer
D — The left edge is a short circuit, Γ = −1.
Reference: Study guide 15.1
A005Section A1 — Advanced RF theory
Adding series reactance on a Smith chart moves you along:
  • AA constant-conductance circle
  • BA constant-resistance circle✓
  • CThe real axis only
  • DThe outer circle
Show answer
B — Series reactance moves along a constant-resistance circle.
Reference: Study guide 15.1
A006Section A1 — Advanced RF theory
What is the reflection coefficient for a 100 Ω load on a 50 Ω line?
  • A0.5
  • B0.2
  • C0.333✓
  • D1.0
Show answer
C — Γ = (100−50)/(100+50) = 0.333.
Reference: Study guide 15.1
A007Section A1 — Advanced RF theory
What return loss corresponds to an SWR of 2:1?
  • A14 dB
  • B9.5 dB✓
  • C3 dB
  • D6 dB
Show answer
B — 2:1 SWR gives about 9.5 dB return loss.
Reference: Study guide 15.2
A008Section A1 — Advanced RF theory
Which matching network uses two capacitors and one inductor?
  • AT network
  • BPi network✓
  • CStub
  • DL network
Show answer
B — A Pi network uses 2 C and 1 L.
Reference: Study guide 15.3
A009Section A1 — Advanced RF theory
Which matching network uses two inductors and one capacitor?
  • APi network
  • BQuarter-wave transformer
  • CL network
  • DT network✓
Show answer
D — A T network uses 2 L and 1 C.
Reference: Study guide 15.3
A010Section A1 — Advanced RF theory
What does a higher Q in a matching network produce?
  • AA wider match
  • BHigher power
  • CLower loss
  • DA narrower match✓
Show answer
D — Higher Q gives a narrower bandwidth match.
Reference: Study guide 15.3
A011Section A1 — Advanced RF theory
What is third-order intercept (IP3)?
  • AThe compression point
  • BThe point where third-order products equal the wanted signal✓
  • CThe maximum input power
  • DThe noise floor
Show answer
B — IP3 is where third-order IMD equals the wanted signal.
Reference: Study guide 15.4
A012Section A1 — Advanced RF theory
What is oscillator phase noise?
  • AHarmonic distortion
  • BAmplitude modulation
  • CLong-term frequency drift
  • DShort-term random frequency fluctuations✓
Show answer
D — Phase noise is short-term random frequency fluctuation.
Reference: Study guide 15.4
A081Section A1 — Advanced RF theory
What does a negative reactance indicate?
  • AA resistive load
  • BAn inductive load
  • CAn open circuit
  • DA capacitive load✓
Show answer
D — Negative reactance is capacitive.
Reference: Study guide 15.1
A082Section A1 — Advanced RF theory
What is at the right edge of a Smith chart?
  • AAn open circuit✓
  • BA perfect match
  • CZero impedance
  • DA short circuit
Show answer
A — The right edge is an open circuit, Gamma = +1.
Reference: Study guide 15.1
A083Section A1 — Advanced RF theory
What is the outer circle of a Smith chart?
  • ATotal reflection✓
  • BA perfect match
  • CA short circuit
  • DAn open circuit
Show answer
A — The outer circle represents total reflection.
Reference: Study guide 15.1
A084Section A1 — Advanced RF theory
Adding shunt reactance on a Smith chart moves you along:
  • AA constant-conductance circle✓
  • BA constant-resistance circle
  • CThe real axis only
  • DThe outer circle
Show answer
A — Shunt reactance moves along a constant-conductance circle.
Reference: Study guide 15.1
A085Section A1 — Advanced RF theory
What is the reflection coefficient for a 25 ohm load on a 50 ohm line?
  • A0.333✓
  • B0.75
  • C0.5
  • D0.25
Show answer
A — Gamma = (25-50)/(25+50) = -0.333, magnitude 0.333.
Reference: Study guide 15.1
A086Section A1 — Advanced RF theory
What is the reflection coefficient for a 150 ohm load on a 50 ohm line?
  • A0.25
  • B0.5✓
  • C0.75
  • D0.333
Show answer
B — Gamma = (150-50)/(150+50) = 0.5.
Reference: Study guide 15.1
A087Section A1 — Advanced RF theory
What is the SWR for a reflection coefficient of 0.5?
  • A3 to 1✓
  • B1.5 to 1
  • C5 to 1
  • D2 to 1
Show answer
A — SWR = (1+0.5)/(1-0.5) = 3.
Reference: Study guide 15.2
A088Section A1 — Advanced RF theory
What is the SWR for a reflection coefficient of 0.333?
  • A2 to 1✓
  • B1.33 to 1
  • C1.5 to 1
  • D3 to 1
Show answer
A — SWR = (1+0.333)/(1-0.333) = 2.
Reference: Study guide 15.2
A089Section A1 — Advanced RF theory
What return loss corresponds to an SWR of 3 to 1?
  • A9.5 dB
  • B3 dB
  • C6 dB✓
  • D14 dB
Show answer
C — 3:1 SWR gives about 6 dB return loss.
Reference: Study guide 15.2
A090Section A1 — Advanced RF theory
What return loss corresponds to an SWR of 1.5 to 1?
  • A14 dB✓
  • B6 dB
  • C9.5 dB
  • D20 dB
Show answer
A — 1.5:1 SWR gives about 14 dB return loss.
Reference: Study guide 15.2
A091Section A1 — Advanced RF theory
Which matching network is low-pass in character?
  • AL network
  • BT network
  • CPi network✓
  • DStub
Show answer
C — A Pi network is low-pass.
Reference: Study guide 15.3
A092Section A1 — Advanced RF theory
Which matching network is high-pass in character?
  • APi network
  • BQuarter-wave transformer
  • CT network✓
  • DL network
Show answer
C — A T network is high-pass.
Reference: Study guide 15.3
A093Section A1 — Advanced RF theory
What does a quarter-wave transformer use to match impedances?
  • ATwo capacitors
  • BA line of the correct impedance and length✓
  • CA resistor
  • DTwo inductors
Show answer
B — A quarter-wave transformer uses a line of specific impedance and length.
Reference: Study guide 15.3
A094Section A1 — Advanced RF theory
What is signal-to-noise ratio?
  • ASignal power times noise power
  • BSignal power minus noise power
  • CNoise power divided by signal power
  • DWanted signal power divided by noise power✓
Show answer
D — SNR is wanted signal over noise power.
Reference: Study guide 15.4
A095Section A1 — Advanced RF theory
What does noise figure describe?
  • ADegradation of SNR through a stage✓
  • BThe receiver gain
  • CThe bandwidth
  • DThe total noise power
Show answer
A — Noise figure is SNR degradation through a stage.
Reference: Study guide 15.4
A096Section A1 — Advanced RF theory
What is blocking in a receiver?
  • ADesensitisation by a strong nearby signal✓
  • BAntenna mismatch
  • CFrequency drift
  • DLoss of audio
Show answer
A — Blocking is desensitisation by a strong signal.
Reference: Study guide 15.4
A097Section A1 — Advanced RF theory
Which stage dominates the noise figure of a receiver chain?
  • AThe audio stage
  • BThe last stage
  • CThe mixer only
  • DThe first stage✓
Show answer
D — The first stage dominates the cascaded noise figure.
Reference: Study guide 15.4
A098Section A1 — Advanced RF theory
What is the advantage of a crystal oscillator?
  • AVery high frequency stability✓
  • BHigh output power
  • CLow cost only
  • DWide tuning range
Show answer
A — Crystals give very high stability.
Reference: Study guide 15.5
A099Section A1 — Advanced RF theory
What does a phase-locked loop do?
  • AMultiplies a reference frequency to produce many frequencies✓
  • BFilters audio
  • CAmplifies RF
  • DMeasures SWR
Show answer
A — A PLL multiplies a reference to synthesise frequencies.
Reference: Study guide 15.5
A100Section A1 — Advanced RF theory
What is frequency stability of 1 ppm at 14 MHz?
  • A1 Hz
  • B140 Hz
  • C1.4 kHz
  • D14 Hz✓
Show answer
D — 1 ppm at 14 MHz is 14 Hz.
Reference: Study guide 15.5
A204Section A1 — Advanced RF theory
What is the purpose of a transmission-line stub?
  • AMeasuring SWR
  • BFiltering audio
  • CCancelling reactance at a specific frequency✓
  • DIncreasing power
Show answer
C — A stub cancels reactance.
Reference: Study guide 15.3
A205Section A1 — Advanced RF theory
What is the Q of a matching network related to?
  • AIts loss
  • BIts impedance
  • CIts power handling
  • DIts bandwidth✓
Show answer
D — Q sets the bandwidth of the match.
Reference: Study guide 15.3
A224Section A1 — Advanced RF theory
What is the purpose of a return-loss measurement?
  • AMeasuring output power
  • BQuantifying how much power is reflected by a mismatch✓
  • CMeasuring field strength
  • DMeasuring frequency
Show answer
B — Return loss quantifies reflected power.
Reference: Study guide 15.2
A225Section A1 — Advanced RF theory
What is the significance of a high Q resonant circuit?
  • ALow loss only
  • BHigh power
  • CWide bandwidth
  • DNarrow bandwidth and sharp selectivity✓
Show answer
D — High Q gives narrow bandwidth and sharp selectivity.
Reference: Study guide 15.3

Section A2 — Advanced electronics

A013Section A2 — Advanced electronics
Which amplifier class has the best linearity?
  • AClass A✓
  • BClass C
  • CClass AB
  • DClass B
Show answer
A — Class A is the most linear.
Reference: Study guide 16.1
A014Section A2 — Advanced electronics
Which amplifier class is most efficient but non-linear?
  • AClass C✓
  • BClass B
  • CClass A
  • DClass AB
Show answer
A — Class C is efficient but non-linear.
Reference: Study guide 16.1
A015Section A2 — Advanced electronics
Which amplifier class is typically used for SSB?
  • AClass D
  • BClass AB✓
  • CClass A
  • DClass C
Show answer
B — Class AB is standard for SSB linear amplification.
Reference: Study guide 16.1
A016Section A2 — Advanced electronics
What is the conduction angle of a Class B amplifier?
  • A90°
  • B180°✓
  • C360°
  • D270°
Show answer
B — Class B conducts for 180°.
Reference: Study guide 16.1
A017Section A2 — Advanced electronics
What is parasitic oscillation?
  • ANormal amplification
  • BA power supply ripple
  • CA type of modulation
  • DUnwanted self-oscillation in an amplifier✓
Show answer
D — Parasitic oscillation is unwanted self-oscillation.
Reference: Study guide 16.2
A018Section A2 — Advanced electronics
How is parasitic oscillation usually cured?
  • AChanging the antenna
  • BFerrite beads, stopper resistors and careful layout✓
  • CReducing bias
  • DIncreasing power
Show answer
B — Ferrite beads, stopper resistors and layout care suppress parasitics.
Reference: Study guide 16.2
A019Section A2 — Advanced electronics
What does neutralisation do in an RF amplifier?
  • AIncreases gain
  • BCancels internal feedback✓
  • CReduces power
  • DImproves cooling
Show answer
B — Neutralisation cancels internal feedback.
Reference: Study guide 16.2
A020Section A2 — Advanced electronics
Which power supply type is quieter for a station?
  • ALinear✓
  • BBoth are equal
  • CSwitching
  • DNeither
Show answer
A — Linear supplies are electrically quieter.
Reference: Study guide 16.3
A021Section A2 — Advanced electronics
What is the main disadvantage of a switching power supply?
  • AWeight
  • BLarge size
  • CLow efficiency
  • DRF noise generation✓
Show answer
D — Switching supplies generate RF noise.
Reference: Study guide 16.3
A022Section A2 — Advanced electronics
Why is component derating important?
  • AIt reduces bandwidth
  • BIt reduces cost
  • CIt improves reliability under real conditions✓
  • DIt increases gain
Show answer
C — Derating improves reliability.
Reference: Study guide 16.4
A101Section A2 — Advanced electronics
What is the conduction angle of a Class A amplifier?
  • A180 degrees
  • B360 degrees✓
  • C90 degrees
  • DLess than 180 degrees
Show answer
B — Class A conducts for the full 360 degrees.
Reference: Study guide 16.1
A102Section A2 — Advanced electronics
What is the conduction angle of a Class C amplifier?
  • A360 degrees
  • B180 degrees
  • CLess than 180 degrees✓
  • D270 degrees
Show answer
C — Class C conducts for less than 180 degrees.
Reference: Study guide 16.1
A103Section A2 — Advanced electronics
Which amplifier class is used for FM finals?
  • AClass AB
  • BClass A
  • CClass C✓
  • DClass B
Show answer
C — Class C suits constant-envelope modes such as FM.
Reference: Study guide 16.1
A104Section A2 — Advanced electronics
What is the typical efficiency of a Class A amplifier?
  • A50 to 60 percent
  • BAbove 85 percent
  • C25 to 35 percent✓
  • D70 to 80 percent
Show answer
C — Class A is typically 25 to 35 percent efficient.
Reference: Study guide 16.1
A105Section A2 — Advanced electronics
What is the typical efficiency of a Class C amplifier?
  • AAbove 95 percent
  • B70 to 80 percent✓
  • C50 to 60 percent
  • D25 to 35 percent
Show answer
B — Class C is typically 70 to 80 percent efficient.
Reference: Study guide 16.1
A106Section A2 — Advanced electronics
What does biasing set in an amplifier?
  • AThe output power
  • BThe bandwidth
  • CThe quiescent current and operating point✓
  • DThe SWR
Show answer
C — Biasing sets the quiescent current and operating point.
Reference: Study guide 16.2
A107Section A2 — Advanced electronics
What is the effect of negative feedback in an amplifier?
  • AIncreased gain only
  • BIncreased distortion
  • CReduced linearity
  • DImproved linearity and stability but reduced gain✓
Show answer
D — Negative feedback improves linearity and stability at the cost of gain.
Reference: Study guide 16.2
A108Section A2 — Advanced electronics
What is a push-pull amplifier?
  • AA single device amplifier
  • BA filter
  • CTwo devices amplifying opposite halves of the waveform✓
  • DA switching supply
Show answer
C — Push-pull uses two devices for opposite half cycles.
Reference: Study guide 16.2
A109Section A2 — Advanced electronics
What is thermal derating?
  • ACooling with a fan
  • BReducing component ratings for higher temperatures✓
  • CIncreasing power at high temperature
  • DMeasuring temperature
Show answer
B — Derating reduces ratings as temperature rises.
Reference: Study guide 16.2
A110Section A2 — Advanced electronics
What does SWR protection do in an amplifier?
  • AImproves linearity
  • BIncreases power
  • CReduces or cuts output when the load mismatch is excessive✓
  • DReduces noise
Show answer
C — SWR protection protects the amplifier from mismatch.
Reference: Study guide 16.2
A111Section A2 — Advanced electronics
What is the main advantage of a linear power supply?
  • AIt is small and light
  • BIt is electrically quiet✓
  • CIt is cheap
  • DIt is highly efficient
Show answer
B — Linear supplies are quiet.
Reference: Study guide 16.3
A112Section A2 — Advanced electronics
What is the main advantage of a switching power supply?
  • ALow RF noise
  • BElectrical quietness
  • CHigh efficiency and small size✓
  • DSimplicity
Show answer
C — Switching supplies are efficient and compact.
Reference: Study guide 16.3
A113Section A2 — Advanced electronics
Why keep loop areas small in EMC-conscious design?
  • ATo reduce radiated and picked-up interference✓
  • BTo improve cooling
  • CTo increase gain
  • DTo reduce cost
Show answer
A — Small loop areas reduce unwanted coupling.
Reference: Study guide 16.4
A114Section A2 — Advanced electronics
Why filter every cable entering an enclosure?
  • ATo increase power
  • BTo improve gain
  • CTo reduce weight
  • DTo prevent interference conducting in or out✓
Show answer
D — Cable filtering blocks conducted interference.
Reference: Study guide 16.4
A115Section A2 — Advanced electronics
What is automatic level control used for?
  • AReducing SWR
  • BIncreasing power
  • CLimiting transmitter drive to prevent distortion✓
  • DFiltering audio
Show answer
C — ALC limits drive to prevent distortion.
Reference: Study guide 16.2
A116Section A2 — Advanced electronics
What is the purpose of a heatsink?
  • ATo match impedance
  • BTo filter RF
  • CTo remove heat from a device✓
  • DTo increase gain
Show answer
C — A heatsink removes heat.
Reference: Study guide 16.2
A117Section A2 — Advanced electronics
What is a MOSFET commonly used for in amateur equipment?
  • ARF power amplification✓
  • BAntenna matching
  • CVoltage regulation only
  • DAudio filtering
Show answer
A — MOSFETs are used for RF power amplification.
Reference: Study guide 16.2
A118Section A2 — Advanced electronics
What is the purpose of a bleeder resistor in a power supply?
  • ATo regulate voltage
  • BTo increase output
  • CTo filter ripple
  • DTo discharge capacitors when power is removed✓
Show answer
D — A bleeder discharges capacitors for safety.
Reference: Study guide 16.3
A206Section A2 — Advanced electronics
What is the purpose of a stopper resistor in an RF stage?
  • AIncreasing gain
  • BReducing noise
  • CSuppressing parasitic oscillation✓
  • DMatching impedance
Show answer
C — Stopper resistors suppress parasitics.
Reference: Study guide 16.2
A207Section A2 — Advanced electronics
What is the purpose of a bypass capacitor?
  • AMatching impedance
  • BProviding a low-impedance path for RF to ground✓
  • CFiltering audio
  • DIncreasing gain
Show answer
B — Bypass capacitors shunt RF to ground.
Reference: Study guide 16.4
A226Section A2 — Advanced electronics
What is the purpose of a low-pass filter in an amplifier output?
  • AIncreasing gain
  • BMatching impedance
  • CRemoving harmonics from the amplified signal✓
  • DReducing noise figure
Show answer
C — The output low-pass filter removes harmonics.
Reference: Study guide 16.2
A227Section A2 — Advanced electronics
What is the purpose of a bias network?
  • AMeasuring power
  • BMatching impedance
  • CFiltering RF
  • DSetting the correct operating point for the device✓
Show answer
D — A bias network sets the operating point.
Reference: Study guide 16.2

Section A3 — DSP, SDR and data systems

A023Section A3 — DSP, SDR and data systems
What does the Nyquist theorem state?
  • Af_s > 2 f_max✓
  • Bf_s > f_max
  • Cf_s < 2 f_max
  • Df_s = f_max
Show answer
A — Sample rate must exceed twice the highest frequency.
Reference: Study guide 17.1
A024Section A3 — DSP, SDR and data systems
What happens if you sample below the Nyquist rate?
  • AHigher SNR
  • BNo effect
  • CIncreased dynamic range
  • DAliasing✓
Show answer
D — Under-sampling causes aliasing.
Reference: Study guide 17.1
A025Section A3 — DSP, SDR and data systems
What prevents aliasing?
  • AA low-pass filter after the DAC
  • BA larger antenna
  • CAn anti-alias filter before the ADC✓
  • DHigher power
Show answer
C — An anti-alias filter before the ADC prevents aliasing.
Reference: Study guide 17.1
A026Section A3 — DSP, SDR and data systems
What is the approximate dynamic range of a 16-bit converter?
  • A48 dB
  • B160 dB
  • C16 dB
  • D96 dB✓
Show answer
D — About 6.02 × 16 ≈ 96 dB.
Reference: Study guide 17.2
A027Section A3 — DSP, SDR and data systems
What does ENOB describe?
  • AThe power consumption
  • BThe sample rate
  • CThe input voltage range
  • DEffective number of bits after real-world impairments✓
Show answer
D — ENOB is the effective number of bits.
Reference: Study guide 17.2
A028Section A3 — DSP, SDR and data systems
What does an FFT produce?
  • AAn audio signal
  • BA time-domain waveform
  • CA frequency spectrum from time-domain samples✓
  • DA power measurement
Show answer
C — FFT converts time domain to frequency domain.
Reference: Study guide 17.3
A029Section A3 — DSP, SDR and data systems
What do IQ signals carry?
  • AAmplitude and phase information✓
  • BFrequency only
  • CPower only
  • DAmplitude only
Show answer
A — IQ carries amplitude and phase.
Reference: Study guide 17.3
A030Section A3 — DSP, SDR and data systems
What is decimation used for?
  • AAmplifying the signal
  • BReducing the sample rate✓
  • CIncreasing the sample rate
  • DFiltering audio
Show answer
B — Decimation reduces the sample rate.
Reference: Study guide 17.3
A031Section A3 — DSP, SDR and data systems
Which modulation method varies both amplitude and phase?
  • APSK
  • BFSK
  • CASK
  • DQAM✓
Show answer
D — QAM varies amplitude and phase.
Reference: Study guide 17.4
A032Section A3 — DSP, SDR and data systems
What is the relationship between bit rate and symbol rate?
  • AThey are unrelated
  • BSymbol rate always exceeds bit rate
  • CBit rate exceeds symbol rate with multi-level modulation✓
  • DBit rate equals symbol rate always
Show answer
C — Multi-level modulation carries more bits per symbol.
Reference: Study guide 17.4
A033Section A3 — DSP, SDR and data systems
What does forward error correction do?
  • ADetects errors only
  • BIncreases power
  • CReduces bandwidth
  • DCorrects errors without retransmission✓
Show answer
D — FEC corrects errors without retransmission.
Reference: Study guide 17.5
A034Section A3 — DSP, SDR and data systems
What is interleaving used for?
  • AReducing power
  • BIncreasing data rate
  • CSpreading burst errors so they can be corrected✓
  • DImproving audio quality
Show answer
C — Interleaving spreads burst errors.
Reference: Study guide 17.5
A119Section A3 — DSP, SDR and data systems
What is the minimum sample rate for a 20 kHz signal?
  • AMore than 40 kHz✓
  • BMore than 80 kHz
  • CMore than 20 kHz
  • DMore than 10 kHz
Show answer
A — Nyquist requires more than twice 20 kHz.
Reference: Study guide 17.1
A120Section A3 — DSP, SDR and data systems
What is aliasing?
  • AHigh frequencies appearing as false low frequencies✓
  • BIncreased noise
  • CFrequency drift
  • DLoss of signal
Show answer
A — Aliasing makes high frequencies appear as false low ones.
Reference: Study guide 17.1
A121Section A3 — DSP, SDR and data systems
What is the dynamic range of a 12-bit converter approximately?
  • A120 dB
  • B48 dB
  • C96 dB
  • D72 dB✓
Show answer
D — About 6.02 x 12 = 72 dB.
Reference: Study guide 17.2
A122Section A3 — DSP, SDR and data systems
What is the dynamic range of a 24-bit converter approximately?
  • A144 dB✓
  • B192 dB
  • C72 dB
  • D96 dB
Show answer
A — About 6.02 x 24 = 144 dB.
Reference: Study guide 17.2
A123Section A3 — DSP, SDR and data systems
What does SFDR describe?
  • ASpurious-free dynamic range✓
  • BFilter delay
  • CSignal fade
  • DSample frequency
Show answer
A — SFDR is spurious-free dynamic range.
Reference: Study guide 17.2
A124Section A3 — DSP, SDR and data systems
What is the difference between FIR and IIR filters?
  • AIIR has no feedback
  • BFIR has a finite impulse response; IIR has feedback and an infinite response✓
  • CFIR is faster only
  • DFIR is analogue; IIR is digital
Show answer
B — FIR is finite; IIR uses feedback.
Reference: Study guide 17.3
A125Section A3 — DSP, SDR and data systems
What is interpolation used for?
  • AReducing the sample rate
  • BIncreasing the sample rate✓
  • CFiltering audio
  • DAmplifying RF
Show answer
B — Interpolation increases the sample rate.
Reference: Study guide 17.3
A126Section A3 — DSP, SDR and data systems
What does direct-sampling SDR do?
  • AUses an analogue demodulator
  • BAvoids the ADC
  • CDigitises the RF signal directly without a mixer✓
  • DUses two mixers
Show answer
C — Direct-sampling SDR digitises RF directly.
Reference: Study guide 17.3
A127Section A3 — DSP, SDR and data systems
Which modulation method uses multiple subcarriers?
  • AOFDM✓
  • BPSK
  • CASK
  • DFSK
Show answer
A — OFDM uses multiple subcarriers.
Reference: Study guide 17.4
A128Section A3 — DSP, SDR and data systems
Which modulation method is most robust against multipath?
  • AOFDM✓
  • BFSK
  • CASK
  • DOOK
Show answer
A — OFDM is robust against multipath.
Reference: Study guide 17.4
A129Section A3 — DSP, SDR and data systems
What is symbol rate measured in?
  • ABits per second
  • BWatts
  • CBaud✓
  • DHertz per second
Show answer
C — Symbol rate is measured in baud.
Reference: Study guide 17.4
A130Section A3 — DSP, SDR and data systems
What determines the bandwidth of a digital signal?
  • ASymbol rate and filtering✓
  • BTransmitter power
  • CAntenna gain
  • DFeedline loss
Show answer
A — Symbol rate and filtering set the bandwidth.
Reference: Study guide 17.4
A131Section A3 — DSP, SDR and data systems
What does a CRC do?
  • AEncrypts data
  • BDetects errors but does not correct them✓
  • CCorrects errors
  • DCompresses data
Show answer
B — A CRC detects but does not correct errors.
Reference: Study guide 17.5
A132Section A3 — DSP, SDR and data systems
What is the advantage of forward error correction?
  • AErrors are corrected without retransmission✓
  • BLower power
  • CWider bandwidth
  • DHigher data rate
Show answer
A — FEC corrects errors without retransmission.
Reference: Study guide 17.5
A133Section A3 — DSP, SDR and data systems
What is required for secure remote station control?
  • AA dummy load
  • BAuthentication and encryption where permitted✓
  • CA directional antenna
  • DA high power amplifier
Show answer
B — Secure control needs authentication and permitted encryption.
Reference: Study guide 17.6
A134Section A3 — DSP, SDR and data systems
What is a fail-safe shutdown in a remote station?
  • AThe station reboots
  • BThe station changes frequency
  • CThe station stops transmitting if control is lost✓
  • DThe station increases power
Show answer
C — Fail-safe shutdown stops transmission if control is lost.
Reference: Study guide 17.6
A135Section A3 — DSP, SDR and data systems
Why must a remote station keep a log?
  • ATo record all transmissions for compliance✓
  • BTo reduce SWR
  • CTo improve gain
  • DTo increase power
Show answer
A — Logging records transmissions for compliance.
Reference: Study guide 17.6
A136Section A3 — DSP, SDR and data systems
What is decimation used for in an SDR chain?
  • AIncreasing the sample rate
  • BAmplifying the signal
  • CFiltering audio
  • DReducing the sample rate to match the required bandwidth✓
Show answer
D — Decimation reduces the sample rate.
Reference: Study guide 17.3
A208Section A3 — DSP, SDR and data systems
What is the purpose of a digital filter?
  • AMeasuring power
  • BSelecting a frequency range in software✓
  • CMatching impedance
  • DAmplifying RF
Show answer
B — Digital filters select frequency ranges in software.
Reference: Study guide 17.3
A209Section A3 — DSP, SDR and data systems
What does a waterfall display show?
  • APower versus distance
  • BImpedance versus frequency
  • CSignal strength over time and frequency✓
  • DTime-domain waveform
Show answer
C — A waterfall shows strength over time and frequency.
Reference: Study guide 17.3
A228Section A3 — DSP, SDR and data systems
What is the purpose of a digital down-converter in an SDR?
  • AMatching impedance
  • BAmplifying RF
  • CShifting and decimating the signal to baseband✓
  • DFiltering audio
Show answer
C — A DDC shifts and decimates to baseband.
Reference: Study guide 17.3
A229Section A3 — DSP, SDR and data systems
What is the purpose of error correction in weak-signal modes?
  • AWidening bandwidth
  • BIncreasing power
  • CReducing latency
  • DRecovering data from noisy signals✓
Show answer
D — Error correction recovers data from noisy signals.
Reference: Study guide 17.5

Section A4 — Advanced antennas and propagation

A035Section A4 — Advanced antennas and propagation
What is the advantage of a phased array?
  • AElectronic beam steering✓
  • BWider bandwidth
  • CHigher power handling
  • DLower cost
Show answer
A — Phased arrays steer the pattern electronically.
Reference: Study guide 18.1
A036Section A4 — Advanced antennas and propagation
What does stacking Yagis achieve?
  • AHigher gain and lower take-off angle✓
  • BOmnidirectional coverage
  • CLower cost
  • DWider bandwidth
Show answer
A — Stacking increases gain and lowers take-off angle.
Reference: Study guide 18.1
A037Section A4 — Advanced antennas and propagation
What is a broadside array?
  • AA single element
  • BElements radiating perpendicular to their line✓
  • CElements radiating along their line
  • DA loop antenna
Show answer
B — Broadside arrays radiate perpendicular to the element line.
Reference: Study guide 18.1
A038Section A4 — Advanced antennas and propagation
What is an end-fire array?
  • AElements radiating perpendicular to their line
  • BA vertical antenna
  • CElements radiating along their line✓
  • DA dipole
Show answer
C — End-fire arrays radiate along the element line.
Reference: Study guide 18.1
A039Section A4 — Advanced antennas and propagation
What inputs does antenna modelling software require?
  • AOnly the power
  • BOnly the frequency
  • COnly the feedline type
  • DElement lengths, spacing, height and ground characteristics✓
Show answer
D — Modelling needs geometry, height and ground data.
Reference: Study guide 18.2
A040Section A4 — Advanced antennas and propagation
Which propagation mode uses temperature inversions?
  • AAuroral
  • BSporadic E
  • CMeteor scatter
  • DTropospheric ducting✓
Show answer
D — Tropospheric ducting relies on temperature inversions.
Reference: Study guide 18.3
A041Section A4 — Advanced antennas and propagation
Which propagation mode produces distorted-sounding signals?
  • AAuroral✓
  • BTropospheric ducting
  • CEME
  • DSporadic E
Show answer
A — Auroral signals sound distorted.
Reference: Study guide 18.3
A042Section A4 — Advanced antennas and propagation
What is EME?
  • AEarth-Moon-Earth communication✓
  • BEnhanced Mode Emission
  • CEmergency Message Exchange
  • DExtended Multi-hop Effect
Show answer
A — EME is moonbounce communication.
Reference: Study guide 18.3
A043Section A4 — Advanced antennas and propagation
Why is rain scatter significant above 1 GHz?
  • ARain increases antenna gain
  • BRain improves polarisation
  • CPrecipitation scatters microwave signals✓
  • DRain reduces path loss
Show answer
C — Rain scatters microwave signals.
Reference: Study guide 18.4
A044Section A4 — Advanced antennas and propagation
Why is the amplifier often mounted at the antenna in microwave systems?
  • ATo reduce cost
  • BTo increase power
  • CTo reduce feedline loss✓
  • DTo improve polarisation
Show answer
C — Feedline loss is severe at microwave frequencies.
Reference: Study guide 18.4
A045Section A4 — Advanced antennas and propagation
What is the take-off angle?
  • AThe antenna height
  • BThe vertical angle of maximum radiation✓
  • CThe feed point impedance
  • DThe horizontal beam heading
Show answer
B — Take-off angle is the vertical angle of peak radiation.
Reference: Study guide 12.3
A046Section A4 — Advanced antennas and propagation
What is the front-to-back ratio?
  • ARatio of power to SWR
  • BRatio of bandwidth to Q
  • CRatio of forward to rearward radiation✓
  • DRatio of gain to loss
Show answer
C — Front-to-back is forward versus rearward radiation.
Reference: Study guide 12.3
A137Section A4 — Advanced antennas and propagation
What is the advantage of a stacked Yagi array?
  • AHigher gain and a lower take-off angle✓
  • BOmnidirectional coverage
  • CLower cost
  • DWider bandwidth
Show answer
A — Stacking raises gain and lowers take-off angle.
Reference: Study guide 18.1
A138Section A4 — Advanced antennas and propagation
What does a phased array allow?
  • AElectronic steering of the radiation pattern✓
  • BWider bandwidth
  • CMechanical rotation only
  • DHigher power handling
Show answer
A — Phased arrays steer the pattern electronically.
Reference: Study guide 18.1
A139Section A4 — Advanced antennas and propagation
What is a log periodic antenna known for?
  • ASmall size
  • BWide bandwidth with moderate gain✓
  • CVery high gain
  • DOmnidirectional coverage
Show answer
B — Log periodic antennas have wide bandwidth.
Reference: Study guide 18.1
A140Section A4 — Advanced antennas and propagation
What is multi-band matching used for?
  • AOperating one antenna on several bands✓
  • BMeasuring SWR
  • CIncreasing gain
  • DReducing noise
Show answer
A — Multi-band matching lets one antenna serve several bands.
Reference: Study guide 18.1
A141Section A4 — Advanced antennas and propagation
What does antenna modelling software predict?
  • AThe band plan
  • BThe weather
  • CThe licence conditions
  • DPattern, gain and impedance✓
Show answer
D — Modelling predicts pattern, gain and impedance.
Reference: Study guide 18.2
A142Section A4 — Advanced antennas and propagation
What is a take-off angle?
  • AThe vertical angle of maximum radiation✓
  • BThe horizontal beam heading
  • CThe feed point impedance
  • DThe antenna height
Show answer
A — Take-off angle is the vertical angle of peak radiation.
Reference: Study guide 18.2
A143Section A4 — Advanced antennas and propagation
What is a rotator used for?
  • AMatching impedance
  • BTurning a directional antenna to a chosen heading✓
  • CFiltering harmonics
  • DMeasuring SWR
Show answer
B — A rotator aims a directional antenna.
Reference: Study guide 18.2
A144Section A4 — Advanced antennas and propagation
Why is wind loading important in mast design?
  • AIt determines the structural strength required✓
  • BIt changes the frequency
  • CIt reduces gain
  • DIt affects the SWR
Show answer
A — Wind loading sets the structural requirement.
Reference: Study guide 18.2
A145Section A4 — Advanced antennas and propagation
What is meteor scatter best suited to?
  • AMicrowave links
  • BLong rag-chews
  • CSatellite work
  • DBrief high-speed data exchanges✓
Show answer
D — Meteor scatter suits brief high-speed exchanges.
Reference: Study guide 18.3
A146Section A4 — Advanced antennas and propagation
What is rain scatter?
  • AReflection from the moon
  • BScattering of microwave signals by precipitation✓
  • CReflection from buildings
  • DReflection from the ionosphere
Show answer
B — Rain scatter is scattering by precipitation.
Reference: Study guide 18.3
A147Section A4 — Advanced antennas and propagation
Why is feedline loss severe at microwave frequencies?
  • ALoss rises with frequency✓
  • BPower is lower
  • CImpedance is higher
  • DCables are longer
Show answer
A — Feedline loss increases with frequency.
Reference: Study guide 18.4
A148Section A4 — Advanced antennas and propagation
Why are microwave antennas physically small?
  • AWavelength is short at high frequencies✓
  • BImpedance is higher
  • CPower is lower
  • DGain is lower
Show answer
A — Short wavelengths mean small antennas.
Reference: Study guide 18.4
A149Section A4 — Advanced antennas and propagation
What is atmospheric absorption significant for?
  • ALF only
  • BMF only
  • CMicrowave and higher frequencies✓
  • DHF only
Show answer
C — Atmospheric absorption matters at microwave frequencies.
Reference: Study guide 18.4
A150Section A4 — Advanced antennas and propagation
What is the purpose of a parabolic antenna?
  • AOmnidirectional HF coverage
  • BMatching impedance
  • CLow noise on HF
  • DHigh gain at microwave frequencies✓
Show answer
D — Parabolic dishes give high microwave gain.
Reference: Study guide 18.4
A151Section A4 — Advanced antennas and propagation
What is EIRP?
  • AEquivalent impedance ratio
  • BEffective input receiver power
  • CEffective isotropic radiated power✓
  • DEstimated interference risk
Show answer
C — EIRP is effective isotropic radiated power.
Reference: Study guide 18.4
A152Section A4 — Advanced antennas and propagation
What is the capture area of an antenna?
  • AIts physical length
  • BIts feed point impedance
  • CIts effective aperture✓
  • DIts bandwidth
Show answer
C — Capture area is the effective aperture.
Reference: Study guide 18.4
A153Section A4 — Advanced antennas and propagation
What is weak-signal operating technique?
  • AUsing wide bandwidth
  • BUsing narrow modes and low noise to work signals near the noise floor✓
  • CUsing FM only
  • DUsing maximum power
Show answer
B — Weak-signal work uses narrow modes near the noise floor.
Reference: Study guide 18.3
A154Section A4 — Advanced antennas and propagation
What is Doppler correction used for in satellite work?
  • AImproving gain
  • BTuning the downlink as the satellite moves✓
  • CIncreasing power
  • DReducing SWR
Show answer
B — Doppler correction compensates for satellite motion.
Reference: Study guide 18.3
A210Section A4 — Advanced antennas and propagation
What is the purpose of a broadband antenna?
  • AOmnidirectional coverage
  • BLow noise
  • CMaximum gain on one band
  • DCovering a wide frequency range without retuning✓
Show answer
D — Broadband antennas cover a wide range.
Reference: Study guide 18.1
A211Section A4 — Advanced antennas and propagation
What is the purpose of a rotator controller?
  • AAiming a directional antenna at a chosen bearing✓
  • BFiltering harmonics
  • CMatching impedance
  • DMeasuring SWR
Show answer
A — A rotator controller aims the antenna.
Reference: Study guide 18.2
A230Section A4 — Advanced antennas and propagation
What is the purpose of a stacked array?
  • AOmnidirectional coverage
  • BWidening bandwidth
  • CIncreasing gain and narrowing the vertical pattern✓
  • DReducing cost
Show answer
C — Stacking raises gain and narrows the vertical pattern.
Reference: Study guide 18.1
A231Section A4 — Advanced antennas and propagation
What is the purpose of a feedline choke at the antenna?
  • AIncreasing gain
  • BSuppressing common-mode current on the shield✓
  • CReducing wind loading
  • DMatching impedance
Show answer
B — A choke suppresses common-mode current.
Reference: Study guide 18.1

Section A5 — RF measurement and test equipment

A047Section A5 — RF measurement and test equipment
What is a dummy load used for?
  • AMeasuring frequency
  • BTesting a transmitter without radiating✓
  • CIncreasing antenna gain
  • DReducing SWR
Show answer
B — A dummy load absorbs RF without radiating.
Reference: Study guide 19
A048Section A5 — RF measurement and test equipment
Why must you attenuate before connecting a transmitter to a spectrum analyser?
  • ATo match impedance
  • BTo reduce harmonics
  • CTo improve accuracy only
  • DTo protect the instrument from damage✓
Show answer
D — Excessive input level damages the analyser.
Reference: Study guide 19
A049Section A5 — RF measurement and test equipment
Which instrument measures impedance and return loss over frequency?
  • AVector network analyser✓
  • BFrequency counter
  • CField strength meter
  • DMultimeter
Show answer
A — A VNA measures impedance and return loss versus frequency.
Reference: Study guide 19
A050Section A5 — RF measurement and test equipment
What does an oscilloscope display?
  • AWaveform in the time domain✓
  • BAmplitude versus frequency
  • CPower versus distance
  • DImpedance versus frequency
Show answer
A — An oscilloscope shows the time-domain waveform.
Reference: Study guide 19
A051Section A5 — RF measurement and test equipment
What is a spectrum analyser used to find?
  • AAudio distortion only
  • BBattery capacity
  • CHarmonics and spurious emissions✓
  • DAntenna gain
Show answer
C — A spectrum analyser reveals harmonics and spurs.
Reference: Study guide 19
A052Section A5 — RF measurement and test equipment
What is the purpose of an antenna analyser?
  • ATo measure audio quality
  • BTo measure output power
  • CTo measure impedance and resonance✓
  • DTo measure frequency stability
Show answer
C — An antenna analyser measures impedance and resonance.
Reference: Study guide 19
A053Section A5 — RF measurement and test equipment
What does a frequency counter measure?
  • AImpedance
  • BField strength
  • CPower
  • DFrequency✓
Show answer
D — A frequency counter measures frequency.
Reference: Study guide 19
A054Section A5 — RF measurement and test equipment
What is a field strength meter used for?
  • AFrequency measurement
  • BAbsolute power measurement
  • CImpedance measurement
  • DRelative RF field measurements✓
Show answer
D — A field strength meter measures relative RF field.
Reference: Study guide 19
A055Section A5 — RF measurement and test equipment
Why should test instruments be properly earthed?
  • ATo reduce SWR
  • BTo improve gain
  • CTo increase power
  • DFor safety and measurement accuracy✓
Show answer
D — Earthing is needed for safety and accuracy.
Reference: Study guide 19
A056Section A5 — RF measurement and test equipment
What is the purpose of an attenuator in test setups?
  • ATo increase signal level
  • BTo reduce signal level to protect instruments✓
  • CTo filter harmonics
  • DTo match impedance
Show answer
B — Attenuators reduce signal level for instrument protection.
Reference: Study guide 19
A155Section A5 — RF measurement and test equipment
What does a multimeter measure?
  • AImpedance and return loss
  • BVoltage, current, resistance and continuity✓
  • CFrequency and power
  • DField strength
Show answer
B — A multimeter measures voltage, current, resistance and continuity.
Reference: Study guide 19
A156Section A5 — RF measurement and test equipment
What does an SWR meter measure?
  • AFrequency
  • BImpedance over frequency
  • CField strength
  • DForward and reflected power✓
Show answer
D — An SWR meter measures forward and reflected power.
Reference: Study guide 19
A157Section A5 — RF measurement and test equipment
What is the purpose of an attenuator in a test setup?
  • ATo reduce signal level and protect instruments✓
  • BTo filter harmonics
  • CTo match impedance
  • DTo increase signal level
Show answer
A — Attenuators reduce level to protect instruments.
Reference: Study guide 19
A158Section A5 — RF measurement and test equipment
What does a signal generator provide?
  • AImpedance measurement
  • BRF power measurement
  • CField strength measurement
  • DA known signal for receiver testing✓
Show answer
D — A signal generator produces known signals.
Reference: Study guide 19
A159Section A5 — RF measurement and test equipment
What does a VNA measure?
  • AFrequency only
  • BPower only
  • CImpedance, SWR and return loss over frequency✓
  • DField strength only
Show answer
C — A VNA measures impedance, SWR and return loss.
Reference: Study guide 19
A160Section A5 — RF measurement and test equipment
What is harmonic measurement used for?
  • AMeasuring battery capacity
  • BChecking transmitter cleanliness✓
  • CMeasuring antenna gain
  • DMeasuring audio quality
Show answer
B — Harmonic measurement checks transmitter cleanliness.
Reference: Study guide 19
A161Section A5 — RF measurement and test equipment
What is intermodulation testing used for?
  • AAssessing receiver performance with strong signals✓
  • BMeasuring audio distortion
  • CMeasuring power supply ripple
  • DMeasuring antenna gain
Show answer
A — IMD testing assesses receiver performance.
Reference: Study guide 19
A162Section A5 — RF measurement and test equipment
What is receiver sensitivity testing used for?
  • AMeasuring field strength
  • BMeasuring output power
  • CFinding the minimum detectable signal level✓
  • DMeasuring impedance
Show answer
C — Sensitivity testing finds the minimum detectable signal.
Reference: Study guide 19
A163Section A5 — RF measurement and test equipment
What is filter response measurement used for?
  • AMeasuring field strength
  • BChecking passband and stopband behaviour✓
  • CMeasuring power
  • DMeasuring frequency
Show answer
B — Filter response measurement checks passband and stopband.
Reference: Study guide 19
A212Section A5 — RF measurement and test equipment
What is the purpose of a return-loss bridge?
  • AFiltering harmonics
  • BMeasuring frequency
  • CMeasuring the match of an antenna system✓
  • DIncreasing power
Show answer
C — A return-loss bridge measures match.
Reference: Study guide 19
A213Section A5 — RF measurement and test equipment
What is the purpose of a calibrated attenuator?
  • AIncreasing power
  • BFiltering harmonics
  • CMatching impedance
  • DProviding a known reduction in signal level✓
Show answer
D — A calibrated attenuator gives a known level reduction.
Reference: Study guide 19
A232Section A5 — RF measurement and test equipment
What is the purpose of a spectrum analyser's resolution bandwidth setting?
  • AControlling the frequency resolution of the display✓
  • BSetting the input attenuation
  • CSetting the reference level
  • DSetting the sweep time
Show answer
A — Resolution bandwidth sets frequency resolution.
Reference: Study guide 19
A233Section A5 — RF measurement and test equipment
What is the purpose of a tracking generator?
  • AMeasuring field strength
  • BProviding a swept signal synchronised with the analyser✓
  • CFiltering harmonics
  • DIncreasing power
Show answer
B — A tracking generator provides a synchronised swept signal.
Reference: Study guide 19

Section A6 — High-power and site safety

A057Section A6 — High-power and site safety
What is the power density formula for a directional antenna in the far field?
  • AS = PG/(4πd²)✓
  • BS = P/G
  • CS = P/(4πd)
  • DS = PGd²
Show answer
A — S = PG/(4πd²).
Reference: Study guide 20.1
A058Section A6 — High-power and site safety
What is the power density 10 m from a 400 W average signal into a 10 dBi antenna?
  • A32 W/m²
  • B0.32 W/m²
  • C3.2 W/m²✓
  • D0.032 W/m²
Show answer
C — S = (400 × 10)/(4π × 100) = 3.2 W/m².
Reference: Study guide 20.1
A059Section A6 — High-power and site safety
How can RF exposure be reduced?
  • AUse a higher gain antenna
  • BLower the antenna
  • CIncrease power
  • DLower power, increase distance, raise the antenna, reduce duty cycle✓
Show answer
D — All four measures reduce exposure.
Reference: Study guide 20.1
A060Section A6 — High-power and site safety
What must be done before working on a high-power amplifier?
  • AConnect a dummy load
  • BIncrease the bias
  • CBleed the capacitors and disconnect power✓
  • DReduce the SWR
Show answer
C — Bleed capacitors and disconnect power first.
Reference: Study guide 20.2
A061Section A6 — High-power and site safety
Where should a safety harness be anchored when climbing?
  • AAt the base of the mast
  • BIt does not matter
  • CBelow the working position
  • DAbove the working position✓
Show answer
D — Anchor above the working position.
Reference: Study guide 20.3
A062Section A6 — High-power and site safety
Why should you never climb a mast alone?
  • ASo someone can raise the alarm and assist✓
  • BIt is only a legal requirement
  • CTo increase speed
  • DTo share tools
Show answer
A — A second person is needed for rescue and assistance.
Reference: Study guide 20.3
A063Section A6 — High-power and site safety
What is the correct first step in station shutdown?
  • AStop transmitting and disconnect the antenna✓
  • BSwitch off the transceiver
  • CSwitch off the mains
  • DSwitch off the amplifier
Show answer
A — Stop transmitting and disconnect the antenna first.
Reference: Study guide 20.4
A064Section A6 — High-power and site safety
Why must amplifier cooling be adequate for continuous duty?
  • ATo improve linearity
  • BTo increase gain
  • CTo reduce SWR
  • DTo prevent overheating and failure✓
Show answer
D — Inadequate cooling causes overheating and failure.
Reference: Study guide 20.2
A164Section A6 — High-power and site safety
What is the power density 5 m from a 100 W average signal into a 10 dBi antenna?
  • A0.318 W/m2
  • B31.8 W/m2
  • C0.0318 W/m2
  • D3.18 W/m2✓
Show answer
D — S = (100 x 10)/(4 pi x 25) = 3.18 W/m2.
Reference: Study guide 20.1
A165Section A6 — High-power and site safety
What is the power density 20 m from a 400 W average signal into a 10 dBi antenna?
  • A7.95 W/m2
  • B79.5 W/m2
  • C0.795 W/m2✓
  • D0.0795 W/m2
Show answer
C — S = (400 x 10)/(4 pi x 400) = 0.795 W/m2.
Reference: Study guide 20.1
A166Section A6 — High-power and site safety
What is the power density 10 m from a 50 W average signal into a 3 dBi antenna?
  • A0.0995 W/m2✓
  • B0.995 W/m2
  • C9.95 W/m2
  • D0.00995 W/m2
Show answer
A — S = (50 x 2)/(4 pi x 100) = 0.0796 W/m2 (G=2 for 3 dBi).
Reference: Study guide 20.1
A167Section A6 — High-power and site safety
Which factor reduces RF exposure?
  • AIncreasing power
  • BReducing duty cycle✓
  • CLowering the antenna
  • DUsing higher gain
Show answer
B — Reducing duty cycle lowers average exposure.
Reference: Study guide 20.1
A168Section A6 — High-power and site safety
Why must amplifier cooling suit continuous duty?
  • ATo prevent overheating and failure✓
  • BTo improve linearity
  • CTo reduce SWR
  • DTo increase gain
Show answer
A — Inadequate cooling causes failure.
Reference: Study guide 20.2
A169Section A6 — High-power and site safety
Why must mains distribution handle surge current?
  • ATo improve gain
  • BTo avoid voltage drop and overheating✓
  • CTo reduce noise
  • DTo increase power
Show answer
B — Surge current can cause voltage drop and overheating.
Reference: Study guide 20.2
A170Section A6 — High-power and site safety
What should be checked before raising a mast?
  • AThe band plan
  • BThe logbook
  • CThe SWR
  • DOverhead power lines✓
Show answer
D — Check for overhead power lines first.
Reference: Study guide 20.3
A171Section A6 — High-power and site safety
What is a gin pole used for?
  • ARaising heavy mast sections✓
  • BFiltering harmonics
  • CMatching impedance
  • DMeasuring SWR
Show answer
A — A gin pole raises heavy sections.
Reference: Study guide 20.3
A172Section A6 — High-power and site safety
Why secure tools when working at height?
  • ATo prevent them falling on people below✓
  • BTo reduce weight
  • CTo improve grip
  • DTo keep them clean
Show answer
A — Securing tools prevents dropped-object injuries.
Reference: Study guide 20.3
A173Section A6 — High-power and site safety
What is the first step in station shutdown?
  • AStop transmitting and disconnect the antenna✓
  • BSwitch off the amplifier
  • CSwitch off the transceiver
  • DSwitch off the mains
Show answer
A — Stop transmitting and disconnect the antenna first.
Reference: Study guide 20.4
A174Section A6 — High-power and site safety
Why let an amplifier cool before switching off the supply?
  • ATo avoid heat soak and component stress✓
  • BTo save power
  • CTo improve gain
  • DTo reduce noise
Show answer
A — Cooling avoids heat soak damage.
Reference: Study guide 20.4
A175Section A6 — High-power and site safety
What should be done with high-voltage areas in a station?
  • ALeave them open for cooling
  • BIgnore them
  • CEnclose and label them clearly✓
  • DCover them with cloth
Show answer
C — High-voltage areas must be enclosed and labelled.
Reference: Study guide 20.2
A214Section A6 — High-power and site safety
What is the purpose of an over-temperature cutout?
  • AIncreasing power
  • BImproving gain
  • CReducing SWR
  • DProtecting an amplifier from thermal damage✓
Show answer
D — An over-temperature cutout protects the amplifier.
Reference: Study guide 20.2
A215Section A6 — High-power and site safety
What is the purpose of an over-current shutdown?
  • AProtecting equipment from excessive current✓
  • BIncreasing power
  • CReducing noise
  • DImproving gain
Show answer
A — Over-current shutdown protects equipment.
Reference: Study guide 20.2
A234Section A6 — High-power and site safety
What is the purpose of an antenna exclusion zone calculation?
  • AMeasuring frequency
  • BMeasuring antenna gain
  • CDetermining the safe distance from a radiating antenna✓
  • DMeasuring SWR
Show answer
C — Exclusion zone calculations determine safe distances.
Reference: Study guide 20.1
A235Section A6 — High-power and site safety
What is the purpose of a station earth bus?
  • AProviding a single common earth reference for all equipment✓
  • BImproving gain
  • CIncreasing power
  • DReducing SWR
Show answer
A — An earth bus gives a single common reference.
Reference: Study guide 20.2

Section A7 — Advanced regulations

A065Section A7 — Advanced regulations
What is the purpose of the ITU Radio Regulations?
  • ATo set antenna heights
  • BTo approve equipment
  • CTo license individual amateurs
  • DTo set international rules for radio services✓
Show answer
D — The ITU RR sets international radio rules.
Reference: Study guide 1.2
A066Section A7 — Advanced regulations
What is the role of the IARU?
  • AManufactures equipment
  • BOperates satellites
  • CCoordinates band plans and represents amateurs internationally✓
  • DIssues national licences
Show answer
C — The IARU coordinates band plans and represents amateurs.
Reference: Study guide 1.2
A067Section A7 — Advanced regulations
What is an emission designator?
  • AA licence class code
  • BA callsign suffix
  • CA power rating
  • DA code describing the characteristics of an emission✓
Show answer
D — Emission designators describe emission characteristics.
Reference: Study guide 1.2
A068Section A7 — Advanced regulations
What does reciprocal operating allow?
  • AOperating without a licence
  • BOperating in another country under an agreement✓
  • CExceeding power limits
  • DUsing any callsign
Show answer
B — Reciprocal arrangements allow operation abroad.
Reference: Study guide 1.3
A069Section A7 — Advanced regulations
What is required for a remote station?
  • AOnly a callsign
  • BOnly a licence
  • CSecure control, identification, logging and fail-safe shutdown✓
  • DOnly an internet connection
Show answer
C — All four requirements apply.
Reference: Study guide 17.6
A070Section A7 — Advanced regulations
What is the operator's responsibility regarding unwanted emissions?
  • AThe manufacturer is responsible
  • BNo one is responsible
  • CThe regulator is responsible
  • DThe operator is responsible for keeping emissions within limits✓
Show answer
D — The operator is responsible for unwanted emissions.
Reference: Study guide 14.2
A176Section A7 — Advanced regulations
Who is responsible for unwanted emissions?
  • ANo one
  • BThe manufacturer
  • CThe operator✓
  • DThe regulator
Show answer
C — The operator is responsible.
Reference: Study guide 14.2
A177Section A7 — Advanced regulations
What is a special-event callsign used for?
  • ABusiness traffic
  • BCommercial advertising
  • CBroadcasting music
  • DMarking a commemorative or public event✓
Show answer
D — Special-event callsigns mark commemorative events.
Reference: Study guide 1.3
A178Section A7 — Advanced regulations
What is a digipeater?
  • AA beacon
  • BA voice repeater
  • CA digital repeater that relays packet data✓
  • DA satellite
Show answer
C — A digipeater relays packet data.
Reference: Study guide 8.3
A179Section A7 — Advanced regulations
What is the purpose of satellite coordination?
  • ATo increase power
  • BTo improve gain
  • CTo manage shared use of satellite frequencies✓
  • DTo reduce SWR
Show answer
C — Coordination manages shared satellite frequencies.
Reference: Study guide 13.3
A180Section A7 — Advanced regulations
What is a club station manager responsible for?
  • AIssuing licences
  • BSetting band plans
  • CPaying for equipment only
  • DEnsuring the station is operated within licence conditions✓
Show answer
D — The manager ensures compliant operation.
Reference: Study guide 1.3
A181Section A7 — Advanced regulations
What is the purpose of station technical documentation?
  • AIncreasing power
  • BRecording the station design and compliance details✓
  • CImproving gain
  • DReducing SWR
Show answer
B — Documentation records design and compliance.
Reference: Study guide 1.3
A182Section A7 — Advanced regulations
What is cross-border operating?
  • AOperating across two bands
  • BOperating on two modes
  • COperating in another country under an agreement✓
  • DOperating two stations
Show answer
C — Cross-border operating is operation abroad under agreement.
Reference: Study guide 1.3
A183Section A7 — Advanced regulations
What is the purpose of an interference investigation?
  • ATo change frequency
  • BTo identify and resolve the cause of interference✓
  • CTo assign blame
  • DTo increase power
Show answer
B — Investigation identifies and resolves interference.
Reference: Study guide 14.2
A184Section A7 — Advanced regulations
What is a beacon used for?
  • AStudying propagation automatically✓
  • BVoice contacts
  • CSatellite work
  • DContest operation
Show answer
A — Beacons study propagation automatically.
Reference: Study guide 8.3
A185Section A7 — Advanced regulations
What is the purpose of an IARU Region 1 band plan?
  • AApproving equipment
  • BSetting power limits
  • CIssuing licences
  • DCoordinating mode and frequency use across the region✓
Show answer
D — Region 1 band plans coordinate regional use.
Reference: Study guide 8.1
A216Section A7 — Advanced regulations
What is the purpose of a licence condition?
  • AReducing SWR
  • BImproving gain
  • CIncreasing power
  • DSetting the terms under which the licence is held✓
Show answer
D — Licence conditions set the terms of the licence.
Reference: Study guide 1.3
A217Section A7 — Advanced regulations
What is the purpose of a station record?
  • ADocumenting the station and its operation✓
  • BIncreasing power
  • CImproving gain
  • DReducing noise
Show answer
A — Station records document the station.
Reference: Study guide 1.3
A218Section A7 — Advanced regulations
What is the purpose of a shared facility agreement?
  • AIncreasing power
  • BSetting the terms for sharing a high site✓
  • CImproving gain
  • DReducing SWR
Show answer
B — Shared facility agreements set site-sharing terms.
Reference: Study guide 1.3
A236Section A7 — Advanced regulations
What is the purpose of an operator's licence conditions?
  • ADefining the privileges and limits of the licence✓
  • BApproving equipment
  • CSetting the band plan
  • DSetting antenna heights
Show answer
A — Licence conditions define privileges and limits.
Reference: Study guide 1.3
A237Section A7 — Advanced regulations
What is the purpose of a national frequency allocation table?
  • AShowing which services may use which frequency bands✓
  • BApproving equipment
  • CSetting power limits
  • DListing licensed operators
Show answer
A — The allocation table shows service allocations by band.
Reference: Study guide 1.2
A238Section A7 — Advanced regulations
What is the purpose of an IARU band plan segment for satellites?
  • AReserving frequencies for satellite uplinks and downlinks✓
  • BReserving frequencies for contests
  • CReserving frequencies for beacons
  • DReserving frequencies for repeaters
Show answer
A — Satellite segments reserve frequencies for satellite work.
Reference: Study guide 8.1

Section A8 — Advanced calculations

A071Section A8 — Advanced calculations
What is the resonant frequency of a 25 µH inductor and a 100 pF capacitor?
  • A31.8 MHz
  • B3.18 MHz✓
  • C1.59 MHz
  • D318 kHz
Show answer
B — f = 1/(2π√(LC)) ≈ 3.18 MHz.
Reference: Study guide 10.3
A072Section A8 — Advanced calculations
Convert 400 W to dBm.
  • A26 dBm
  • B56 dBm✓
  • C46 dBm
  • D66 dBm
Show answer
B — 10 log₁₀(400/0.001) = 56 dBm.
Reference: Study guide 10.8
A073Section A8 — Advanced calculations
What is the impedance of a circuit with R = 30 Ω and net reactance of 40 Ω?
  • A50 Ω✓
  • B70 Ω
  • C10 Ω
  • D1200 Ω
Show answer
A — Z = √(30² + 40²) = 50 Ω.
Reference: Study guide 10.2
A074Section A8 — Advanced calculations
A 6 dB increase in power represents what ratio?
  • A×6
  • B×4✓
  • C×10
  • D×2
Show answer
B — +6 dB is ×4 power.
Reference: Study guide 10.8
A075Section A8 — Advanced calculations
What is the power density 20 m from a 100 W signal into a 6 dBi antenna?
  • A7.9 W/m²
  • B0.0079 W/m²
  • C0.079 W/m²✓
  • D0.79 W/m²
Show answer
C — S = (100 × 3.98)/(4π × 400) ≈ 0.079 W/m².
Reference: Study guide 20.1
A076Section A8 — Advanced calculations
What is the return loss for a reflection coefficient of 0.5?
  • A6 dB✓
  • B9.5 dB
  • C3 dB
  • D12 dB
Show answer
A — −20 log₁₀(0.5) = 6 dB.
Reference: Study guide 15.2
A077Section A8 — Advanced calculations
What is the electrical length of 10 m of coax with a velocity factor of 0.66?
  • A15.2 m
  • B10 m
  • C0.66 m
  • D6.6 m✓
Show answer
D — Electrical length = 10 × 0.66 = 6.6 m.
Reference: Study guide 12.1
A078Section A8 — Advanced calculations
A transmitter produces 100 W and the DC input is 200 W. What is the efficiency?
  • A75%
  • B25%
  • C100%
  • D50%✓
Show answer
D — Efficiency = 100/200 = 50%.
Reference: Study guide 11.2
A079Section A8 — Advanced calculations
What is the gain in dBi of an antenna rated at 10 dBd?
  • A7.85 dBi
  • B10 dBi
  • C12.15 dBi✓
  • D20 dBi
Show answer
C — dBi = dBd + 2.15 = 12.15 dBi.
Reference: Study guide 12.3
A080Section A8 — Advanced calculations
What is the wavelength at 144.2 MHz?
  • A2.08 cm
  • B0.208 m
  • C2.08 m✓
  • D20.8 m
Show answer
C — λ = 300/144.2 = 2.08 m.
Reference: Study guide 3.8
A186Section A8 — Advanced calculations
What is the resonant frequency of a 50 uH inductor and a 50 pF capacitor?
  • A318 kHz
  • B1.59 MHz
  • C31.8 MHz
  • D3.18 MHz✓
Show answer
D — f = 1/(2 pi sqrt(LC)) = 3.18 MHz.
Reference: Study guide 10.3
A187Section A8 — Advanced calculations
What is the resonant frequency of a 100 uH inductor and a 25 pF capacitor?
  • A3.18 MHz✓
  • B318 kHz
  • C31.8 MHz
  • D1.59 MHz
Show answer
A — f = 1/(2 pi sqrt(LC)) = 3.18 MHz.
Reference: Study guide 10.3
A188Section A8 — Advanced calculations
What is the resonant frequency of a 1 mH inductor and a 100 pF capacitor?
  • A50.3 kHz
  • B5.03 MHz
  • C1.59 MHz
  • D503 kHz✓
Show answer
D — f = 1/(2 pi sqrt(LC)) = 503 kHz.
Reference: Study guide 10.3
A189Section A8 — Advanced calculations
Convert 25 W to dBm.
  • A54 dBm
  • B25 dBm
  • C34 dBm
  • D44 dBm✓
Show answer
D — 10 log10(25/0.001) = 44 dBm.
Reference: Study guide 10.8
A190Section A8 — Advanced calculations
Convert 200 W to dBm.
  • A43 dBm
  • B63 dBm
  • C53 dBm✓
  • D23 dBm
Show answer
C — 10 log10(200/0.001) = 53 dBm.
Reference: Study guide 10.8
A191Section A8 — Advanced calculations
Convert 1000 W to dBm.
  • A30 dBm
  • B70 dBm
  • C60 dBm✓
  • D50 dBm
Show answer
C — 10 log10(1000/0.001) = 60 dBm.
Reference: Study guide 10.8
A192Section A8 — Advanced calculations
What is the impedance of a circuit with R = 60 ohm and net reactance 80 ohm?
  • A4800 ohm
  • B100 ohm✓
  • C140 ohm
  • D20 ohm
Show answer
B — Z = sqrt(60^2 + 80^2) = 100 ohm.
Reference: Study guide 10.2
A193Section A8 — Advanced calculations
What is the impedance of a circuit with R = 12 ohm and net reactance 16 ohm?
  • A28 ohm
  • B20 ohm✓
  • C192 ohm
  • D4 ohm
Show answer
B — Z = sqrt(12^2 + 16^2) = 20 ohm.
Reference: Study guide 10.2
A194Section A8 — Advanced calculations
What is the impedance of a circuit with R = 9 ohm and net reactance 12 ohm?
  • A3 ohm
  • B15 ohm✓
  • C108 ohm
  • D21 ohm
Show answer
B — Z = sqrt(9^2 + 12^2) = 15 ohm.
Reference: Study guide 10.2
A195Section A8 — Advanced calculations
A 12 dB increase in power represents what ratio?
  • AAbout 12 times
  • BAbout 16 times✓
  • CAbout 4 times
  • DAbout 24 times
Show answer
B — 12 dB is about x16 power.
Reference: Study guide 10.8
A196Section A8 — Advanced calculations
A 20 dB increase in power represents what ratio?
  • A10 times
  • B100 times✓
  • C200 times
  • D20 times
Show answer
B — 20 dB is x100 power.
Reference: Study guide 10.8
A197Section A8 — Advanced calculations
What is the return loss for a reflection coefficient of 0.2?
  • A9.5 dB
  • B20 dB
  • C14 dB✓
  • D6 dB
Show answer
C — -20 log10(0.2) = 14 dB.
Reference: Study guide 15.2
A198Section A8 — Advanced calculations
What is the return loss for a reflection coefficient of 0.333?
  • A9.5 dB✓
  • B14 dB
  • C6 dB
  • D3 dB
Show answer
A — -20 log10(0.333) = 9.5 dB.
Reference: Study guide 15.2
A199Section A8 — Advanced calculations
What is the electrical length of 30 m of coax with a velocity factor of 0.8?
  • A2.4 m
  • B30 m
  • C37.5 m
  • D24 m✓
Show answer
D — Electrical length = 30 x 0.8 = 24 m.
Reference: Study guide 12.1
A200Section A8 — Advanced calculations
A transmitter produces 150 W RF from 300 W DC input. What is the efficiency?
  • A25 percent
  • B75 percent
  • C100 percent
  • D50 percent✓
Show answer
D — Efficiency = 150/300 = 50 percent.
Reference: Study guide 11.2
A201Section A8 — Advanced calculations
A transmitter produces 60 W RF from 100 W DC input. What is the efficiency?
  • A80 percent
  • B60 percent✓
  • C40 percent
  • D100 percent
Show answer
B — Efficiency = 60/100 = 60 percent.
Reference: Study guide 11.2
A202Section A8 — Advanced calculations
What is the gain in dBi of an antenna rated at 15 dBd?
  • A17.15 dBi✓
  • B15 dBi
  • C30 dBi
  • D12.85 dBi
Show answer
A — dBi = dBd + 2.15 = 17.15 dBi.
Reference: Study guide 12.3
A203Section A8 — Advanced calculations
What is the wavelength at 432 MHz?
  • A6.94 m
  • B0.0694 m
  • C1.44 m
  • D0.694 m✓
Show answer
D — Wavelength = 300/432 = 0.694 m.
Reference: Study guide 3.8
A219Section A8 — Advanced calculations
What is the power density 15 m from a 200 W average signal into a 6 dBi antenna?
  • A0.282 W/m2✓
  • B28.2 W/m2
  • C2.82 W/m2
  • D0.0282 W/m2
Show answer
A — S = (200 x 3.98)/(4 pi x 225) = 0.282 W/m2.
Reference: Study guide 20.1
A220Section A8 — Advanced calculations
What is the power density 8 m from a 100 W average signal into a 12 dBi antenna?
  • A0.0198 W/m2
  • B19.8 W/m2
  • C0.198 W/m2
  • D1.98 W/m2✓
Show answer
D — S = (100 x 15.85)/(4 pi x 64) = 1.97 W/m2.
Reference: Study guide 20.1
A221Section A8 — Advanced calculations
What is the wavelength at 1296 MHz?
  • A2.31 m
  • B0.231 m✓
  • C0.0231 m
  • D1.296 m
Show answer
B — Wavelength = 300/1296 = 0.231 m.
Reference: Study guide 3.8
A222Section A8 — Advanced calculations
What is the length of a quarter-wave vertical for 432 MHz?
  • A0.331 m
  • B0.083 m
  • C0.165 m✓
  • D0.432 m
Show answer
C — Length = 71.5/432 = 0.165 m.
Reference: Study guide 5.3
A223Section A8 — Advanced calculations
What is the length of a half-wave dipole for 50 MHz?
  • A5.72 m
  • B2.86 m✓
  • C1.43 m
  • D50 m
Show answer
B — Length = 143/50 = 2.86 m.
Reference: Study guide 5.3
A239Section A8 — Advanced calculations
What is the power density 12 m from a 150 W average signal into a 9 dBi antenna?
  • A0.0656 W/m2
  • B6.56 W/m2
  • C0.656 W/m2✓
  • D65.6 W/m2
Show answer
C — S = (150 x 7.94)/(4 pi x 144) = 0.659 W/m2.
Reference: Study guide 20.1
A240Section A8 — Advanced calculations
What is the length of a half-wave dipole for 28 MHz?
  • A5.11 m✓
  • B28 m
  • C10.2 m
  • D2.55 m
Show answer
A — Length = 143/28 = 5.11 m.
Reference: Study guide 5.3

Answer key

Novice

QAnsQAnsQAnsQAns
N001BN031CN061DN091D
N002BN032CN062CN092A
N003CN033AN063AN093D
N004BN034CN064CN094C
N005AN035DN065AN095B
N006AN036AN066BN096B
N007CN037AN067AN097A
N008CN038AN068AN098A
N009BN039AN069DN099B
N010DN040AN070AN100A
N011AN041DN071AN101B
N012CN042CN072BN102B
N013CN043AN073AN103A
N014DN044DN074DN104D
N015CN045DN075AN105A
N016AN046CN076AN106B
N017BN047DN077BN107C
N018AN048AN078DN108D
N019CN049CN079BN109D
N020BN050BN080DN110A
N021AN051BN081DN111D
N022DN052CN082BN112C
N023DN053BN083BN113B
N024AN054CN084BN114B
N025CN055DN085AN115C
N026BN056CN086AN116A
N027DN057CN087DN117B
N028AN058CN088CN118D
N029AN059DN089CN119D
N030CN060BN090CN120A

General

QAnsQAnsQAnsQAns
G001AG046BG091DG136D
G002BG047AG092DG137D
G003BG048BG093BG138A
G004DG049DG094CG139B
G005CG050CG095DG140A
G006DG051DG096DG141C
G007BG052DG097AG142A
G008BG053BG098DG143C
G009DG054AG099BG144A
G010BG055DG100CG145D
G011BG056DG101AG146B
G012CG057DG102AG147B
G013DG058AG103CG148D
G014AG059AG104BG149A
G015AG060DG105BG150D
G016BG061AG106AG151A
G017CG062BG107AG152A
G018CG063DG108BG153D
G019AG064BG109CG154D
G020CG065AG110DG155D
G021DG066DG111AG156C
G022AG067CG112AG157A
G023AG068BG113AG158A
G024BG069AG114CG159D
G025CG070BG115AG160B
G026DG071AG116DG161A
G027CG072CG117DG162B
G028AG073DG118BG163C
G029AG074BG119CG164B
G030DG075CG120CG165C
G031AG076DG121DG166C
G032CG077DG122BG167C
G033DG078AG123CG168D
G034BG079AG124BG169A
G035AG080DG125BG170D
G036BG081AG126DG171A
G037BG082CG127DG172D
G038AG083CG128BG173C
G039CG084AG129DG174B
G040CG085AG130CG175B
G041BG086AG131BG176C
G042DG087DG132BG177A
G043CG088BG133DG178A
G044BG089DG134CG179D
G045AG090BG135DG180C

Advanced

QAnsQAnsQAnsQAns
A001AA061DA121DA181B
A002AA062AA122AA182C
A003CA063AA123AA183B
A004DA064DA124BA184A
A005BA065DA125BA185D
A006CA066CA126CA186D
A007BA067DA127AA187A
A008BA068BA128AA188D
A009DA069CA129CA189D
A010DA070DA130AA190C
A011BA071BA131BA191C
A012DA072BA132AA192B
A013AA073AA133BA193B
A014AA074BA134CA194B
A015BA075CA135AA195B
A016BA076AA136DA196B
A017DA077DA137AA197C
A018BA078DA138AA198A
A019BA079CA139BA199D
A020AA080CA140AA200D
A021DA081DA141DA201B
A022CA082AA142AA202A
A023AA083AA143BA203D
A024DA084AA144AA204C
A025CA085AA145DA205D
A026DA086BA146BA206C
A027DA087AA147AA207B
A028CA088AA148AA208B
A029AA089CA149CA209C
A030BA090AA150DA210D
A031DA091CA151CA211A
A032CA092CA152CA212C
A033DA093BA153BA213D
A034CA094DA154BA214D
A035AA095AA155BA215A
A036AA096AA156DA216D
A037BA097DA157AA217A
A038CA098AA158DA218B
A039DA099AA159CA219A
A040DA100DA160BA220D
A041AA101BA161AA221B
A042AA102CA162CA222C
A043CA103CA163BA223B
A044CA104CA164DA224B
A045BA105BA165CA225D
A046CA106CA166AA226C
A047BA107DA167BA227D
A048DA108CA168AA228C
A049AA109BA169BA229D
A050AA110CA170DA230C
A051CA111BA171AA231B
A052CA112CA172AA232A
A053DA113AA173AA233B
A054DA114DA174AA234C
A055DA115CA175CA235A
A056BA116CA176CA236A
A057AA117AA177DA237A
A058CA118DA178CA238A
A059DA119AA179CA239C
A060CA120AA180DA240A

Formula sheet

QuantityFormula
Ohm's law\(V = IR\)
Power\(P = VI = I^2R = V^2/R\)
Resistors in series\(R = R_1 + R_2 + \dots\)
Resistors in parallel\(1/R = 1/R_1 + 1/R_2 + \dots\)
Wavelength\(\lambda = 300 / f\ (\text{MHz})\)
Period\(T = 1/f\)
Capacitive reactance\(X_C = 1/(2\pi fC)\)
Inductive reactance\(X_L = 2\pi fL\)
Impedance\(Z = \sqrt{R^2 + (X_L - X_C)^2}\)
Resonance\(f_r = 1/(2\pi\sqrt{LC})\)
Q factor\(Q = f_r / \text{bandwidth}\)
Decibels (power)\(\text{dB} = 10\log_{10}(P_2/P_1)\)
Decibels (voltage)\(\text{dB} = 20\log_{10}(V_2/V_1)\)
dBm\(10\log_{10}(P/1\ \text{mW})\)
Reflection coefficient\(\Gamma = (Z_L - Z_0)/(Z_L + Z_0)\)
SWR\((1 + |Gamma|)/(1 - |Gamma|)\)
Return loss\(-20\log_{10}|Gamma|\)
Half-wave dipole\(143 / f\ (\text{MHz})\) metres
Quarter-wave vertical\(71.5 / f\ (\text{MHz})\) metres
Peak from RMS\(V_{pk} = 1.414 \times V_{RMS}\)
Nyquist limit\(f_s > 2 f_{max}\)
Power density\(S = PG/(4\pi d^2)\)
dBd to dBi\(\text{dBi} = \text{dBd} + 2.15\)
Efficiency\(\eta = P_{RF} / P_{DC}\)

Important licence condition

This is a training and examination proposal. No operator should assume a privilege simply because it appears in this pool.

A Nigerian amateur may transmit only on the bands, frequencies, modes, bandwidths, station types and maximum power levels written on their current licence or authorisation from the Federal Ministry of Communications, Innovation and Digital Economy.