US Amateur Radio - Amateur Extra (Element 4, 2020-2024) Practice Test

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1. - E0A08

What does SAR measure?

Select	Answer
A	Signal Amplification Rating
B	The rate at which RF energy is absorbed by the body
C	The rate of RF energy reflected from stationary terrain
D	Synthetic Aperture Ratio of the human body

2. - E1A11

Which of the following describes authorization or licensing required when operating an amateur station aboard a U.S.-registered vessel in international waters?

Select	Answer
A	Any amateur license with an FCC Marine or Aircraft endorsement
B	An unrestricted Radiotelephone Operator Permit
C	Any FCC-issued amateur license
D	Only General Class or higher amateur licenses

3. - E1B07

To what type of regulations does PRB-1 apply?

Select	Answer
A	FAA tower height limits
B	Use of wireless devices in vehicles
C	State and local zoning
D	Homeowners associations

4. - E1C08

What is the maximum permissible duration of a remotely controlled station's transmissions if its control link malfunctions?

Select	Answer
A	10 minutes
B	3 minutes
C	30 seconds
D	5 minutes

5. - E1D04

Which of the following is required in the identification transmissions from a balloon-borne telemetry station?

Select	Answer
A	The station's six-character Maidenhead grid locator
B	All these choices are correct
C	Call sign
D	The output power of the balloon transmitter

6. - E1E07

What should a VE do if a candidate fails to comply with the examiner's instructions during an amateur operator license examination?

Select	Answer
A	Immediately terminate the candidate's examination
B	Warn the candidate that continued failure to comply will result in termination of the examination
C	Allow the candidate to complete the examination, but invalidate the results
D	Immediately terminate everyone's examination and close the session

7. - E1F10

Who may be the control operator of an auxiliary station?

Select	Answer
A	Only General, Advanced or Amateur Extra Class operators
B	Only Amateur Extra Class operators
C	Only Technician, General, Advanced or Amateur Extra Class operators
D	Any licensed amateur operator

8. - E2A02

Which of the following occurs when a satellite is using an inverting linear transponder?

Select	Answer
A	Signal position in the band is reversed
B	All these choices are correct
C	Doppler shift is reduced because the uplink and downlink shifts are in opposite directions
D	Upper sideband on the uplink becomes lower sideband on the downlink, and vice versa

9. - E2B06

What is vestigial sideband modulation?

Select	Answer
A	Spread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation
B	Narrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier
C	Amplitude modulation in which one complete sideband and a portion of the other are transmitted
D	A type of modulation in which one sideband is inverted

10. - E2C04

Which of the following frequencies are sometimes used for amateur radio mesh networks?

Select	Answer
A	Cable TV channels 41 through 43
B	The 60 meter band channel centered on 5373 kHz
C	HF frequencies where digital communications are permitted
D	Frequencies shared with various unlicensed wireless data services

11. - E2D05

What is one advantage of the JT65 mode?

Select	Answer
A	Permits fast-scan TV transmissions over narrow bandwidth
B	Uses only a 65 Hz bandwidth
C	Easily copied by ear if necessary
D	The ability to decode signals which have a very low signal-to-noise ratio

12. - E2E04

What is indicated when one of the ellipses in an FSK crossed-ellipse display suddenly disappears?

Select	Answer
A	The mark and space signal have been inverted
B	The receiver has drifted 5 kHz from the desired receive frequency
C	Selective fading has occurred
D	One of the signal filters is saturated

13. - E3A05

Tropospheric propagation of microwave signals often occurs in association with what phenomenon?

Select	Answer
A	Lightning discharges
B	Grayline
C	Warm and cold fronts
D	Sprites and jets

14. - E3B02

What is the approximate maximum range for signals using transequatorial propagation?

Select	Answer
A	1000 miles
B	5000 miles
C	7500 miles
D	2500 miles

15. - E3C12

How does the maximum range of ground-wave propagation change when the signal frequency is increased?

Select	Answer
A	It peaks at roughly 14 MHz
B	It stays the same
C	It decreases
D	It increases

16. - E4A10

Which of the following displays multiple digital signal states simultaneously?

Select	Answer
A	Logic analyzer
B	Modulation monitor
C	Network analyzer
D	Bit error rate tester

17. - E4B01

Which of the following factors most affects the accuracy of a frequency counter?

Select	Answer
A	Temperature coefficient of the logic
B	Time base accuracy
C	Decade divider accuracy
D	Input attenuator accuracy

18. - E4C10

What is an advantage of having a variety of receiver IF bandwidths from which to select?

Select	Answer
A	Receive bandwidth can be set to match the modulation bandwidth, maximizing signal-to-noise ratio and minimizing interference
B	Receiver power consumption can be reduced when wider bandwidth is not required
C	Multiple frequencies can be received simultaneously if desired
D	The noise figure of the RF amplifier can be adjusted to match the modulation type, thus increasing receiver sensitivity

19. - E4D01

What is meant by the blocking dynamic range of a receiver?

Select	Answer
A	The minimum difference in dB between the levels of two FM signals that will cause one signal to block the other
B	The minimum difference in dB between two signals which produce third-order intermodulation products greater than the noise floor
C	The difference in dB between the noise floor and the third-order intercept point
D	The difference in dB between the noise floor and the level of an incoming signal that will cause 1 dB of gain compression

20. - E4E07

Which of the following can cause shielded cables to radiate or receive interference?

Select	Answer
A	Use of braided shielding material
B	Tying all ground connections to a common point resulting in differential-mode currents in the shield
C	Low inductance ground connections at both ends of the shield
D	Common-mode currents on the shield and conductors

21. - E5A03

What is the magnitude of the impedance of a series RLC circuit at resonance?

Select	Answer
A	Approximately equal to capacitive reactance
B	Approximately equal to circuit resistance
C	High, as compared to the circuit resistance
D	Approximately equal to inductive reactance

22. - E5B01

What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the applied voltage or to discharge to 36.8% of its initial voltage?

Select	Answer
A	An exponential rate of one
B	One time constant
C	One exponential period
D	A time factor of one

23. - E5C05

What is the name of the diagram used to show the phase relationship between impedances at a given frequency?

Select	Answer
A	Far field diagram
B	Phasor diagram
C	Near field diagram
D	Venn diagram

24. - E5D10

How can the true power be determined in an AC circuit where the voltage and current are out of phase?

Select	Answer
A	By dividing the reactive power by the power factor
B	By dividing the apparent power by the power factor
C	By multiplying the reactive power by the power factor
D	By multiplying the apparent power by the power factor

25. - E6A03

Why does a PN-junction diode not conduct current when reverse biased?

Select	Answer
A	Holes in P-type material and electrons in the N-type material are separated by the applied voltage, widening the depletion region
B	Only P-type semiconductor material can conduct current
C	Excess holes in P-type material combine with the electrons in N-type material, converting the entire diode into an insulator
D	Only N-type semiconductor material can conduct current

26. - E6B06

Which of the following is a common use of a Schottky diode?

Select	Answer
A	As a VHF/UHF mixer or detector
B	As a rectifier in high current power supplies
C	As a variable capacitance in an automatic frequency control circuit
D	As a constant voltage reference in a power supply

27. - E6C05

What is an advantage of CMOS logic devices over TTL devices?

Select	Answer
A	Immune to damage from static discharge
B	Lower power consumption
C	Differential output capability
D	Lower distortion

28. - E6D08

What is one reason for using powdered-iron cores rather than ferrite cores in an inductor?

Select	Answer
A	Powdered-iron cores generally require fewer turns to produce a given inductance
B	Powdered-iron cores generally maintain their characteristics at higher currents
C	Powdered-iron cores use smaller diameter wire for the same inductance
D	Powdered-iron cores generally have greater initial permeability

29. - E6E09

Which of the following component package types would be most suitable for use at frequencies above the HF range?

Select	Answer
A	Radial lead
B	Axial lead
C	Surface mount
D	TO-220

30. - E6F01

What absorbs the energy from light falling on a photovoltaic cell?

Select	Answer
A	Electrons
B	Photons
C	Holes
D	Protons

31. - E7A04

How many flip-flops are required to divide a signal frequency by 4?

Select	Answer
A	2
B	1
C	8
D	4

32. - E7B10

In Figure E7-1, what is the purpose of R1 and R2?

Select	Answer
A	Load resistors
B	Feedback
C	Voltage divider bias
D	Self bias

33. - E7C01

How are the capacitors and inductors of a low-pass filter Pi-network arranged between the network's input and output?

Select	Answer
A	Two capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground
B	A capacitor is connected between the input and ground, another capacitor is connected between the output and ground, and an inductor is connected between input and output
C	An inductor is connected between the input and ground, another inductor is connected between the output and ground, and a capacitor is connected between the input and output
D	Two inductors are in series between the input and output, and a capacitor is connected between the two inductors and ground

34. - E7D09

What is the main reason to use a charge controller with a solar power system?

Select	Answer
A	Matching of day and night charge rates
B	Prevention of battery undercharge
C	Control of electrolyte levels during battery discharge
D	Prevention of battery damage due to overcharge

35. - E7E07

What is meant by the term "baseband" in radio communications?

Select	Answer
A	The basic oscillator frequency in an FM transmitter that is multiplied to increase the deviation and carrier frequency
B	The frequency range occupied by a message signal prior to modulation
C	The unmodulated bandwidth of the transmitted signal
D	The lowest frequency band that the transmitter or receiver covers

36. - E7F14

Which of the following would allow a digital signal processing filter to create a sharper filter response?

Select	Answer
A	Complex phasor representations
B	Double-precision math routines
C	More taps
D	Higher data rate

37. - E7G05

How can unwanted ringing and audio instability be prevented in an op-amp RC audio filter circuit?

Select	Answer
A	Increase both gain and Q
B	Restrict gain but increase Q
C	Restrict both gain and Q
D	Restrict Q but increase gain

38. - E7H03

How is positive feedback supplied in a Hartley oscillator?

Select	Answer
A	Through a capacitive divider
B	Through link coupling
C	Through a neutralizing capacitor
D	Through a tapped coil

39. - E8A03

What type of wave does a Fourier analysis show to be made up of sine waves of a given fundamental frequency plus all its harmonics?

Select	Answer
A	A sawtooth wave
B	A sine wave
C	A square wave
D	A cosine wave

40. - E8B05

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus-or-minus 5 kHz when the maximum modulation frequency is 3 kHz?

Select	Answer
A	0.6
B	1.67
C	0.167
D	60

41. - E8C12

What factors affect the bandwidth of a transmitted CW signal?

Select	Answer
A	All these choices are correct
B	IF bandwidth and Q
C	Keying speed and shape factor (rise and fall time)
D	Modulation index and output power

42. - E8D02

What spread spectrum communications technique uses a high-speed binary bit stream to shift the phase of an RF carrier?

Select	Answer
A	Frequency hopping
B	Binary phase-shift keying
C	Phase compandored spread spectrum
D	Direct sequence

43. - E9A01

What is an isotropic antenna?

Select	Answer
A	A horizontally polarized antenna used to compare Yagi antennas
B	A grounded antenna used to measure Earth conductivity
C	A theoretical, omnidirectional antenna used as a reference for antenna gain
D	A spacecraft antenna used to direct signals toward Earth

44. - E9B07

How does the total amount of radiation emitted by a directional gain antenna compare with the total amount of radiation emitted from a theoretical isotropic antenna, assuming each is driven by the same amount of power?

Select	Answer
A	They are the same
B	The radiation from the isotropic antenna is 2.15 dB stronger than that from the directional antenna
C	The total amount of radiation from the directional antenna is increased by the gain of the antenna
D	The total amount of radiation from the directional antenna is stronger by its front-to-back ratio

45. - E9C13

How does the radiation pattern of a horizontally polarized 3-element beam antenna vary with increasing height above ground?

Select	Answer
A	The takeoff angle of the lowest elevation lobe decreases
B	The horizontal beamwidth increases
C	The takeoff angle of the lowest elevation lobe increases
D	The horizontal beamwidth decreases

46. - E9D12

Which of the following would provide the best RF ground for your station?

Select	Answer
A	An electrically short connection to 3 or 4 interconnected ground rods driven into the Earth
B	An electrically short connection to 3 or 4 interconnected ground rods via a series RF choke
C	An electrically short connection to a metal water pipe
D	A 50-ohm resistor connected to ground

47. - E9E04

What is the purpose of the series capacitor in a gamma-type antenna matching network?

Select	Answer
A	To provide DC isolation between the feed line and the antenna
B	To cancel the inductive reactance of the matching network
C	To transform the antenna impedance to a higher value
D	To provide a rejection notch that prevents the radiation of harmonics

48. - E9F07

How does ladder line compare to small-diameter coaxial cable such as RG-58 at 50 MHz?

Select	Answer
A	Higher SWR
B	Lower loss
C	Lower velocity factor
D	Smaller reflection coefficient

49. - E9G02

What type of coordinate system is used in a Smith chart?

Select	Answer
A	Voltage circles and current arcs
B	Voltage lines and current chords
C	Resistance circles and reactance arcs
D	Resistance lines and reactance chords

50. - E9H03

What is Receiving Directivity Factor (RDF)?

Select	Answer
A	Forward gain compared to the gain in the reverse direction
B	Relative directivity compared to a dipole
C	Relative directivity compared to isotropic
D	Forward gain compared to average gain over the entire hemisphere

Figure E7-1