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

Logging in (or registering) will help the system to select questions that you need to focus on.

1. - E0A06

Why are there separate electric (E) and magnetic (H) field MPE limits?

Select	Answer
A	All these choices are correct
B	The body reacts to electromagnetic radiation from both the E and H fields
C	Ground reflections and scattering make the field strength vary with location
D	E field and H field radiation intensity peaks can occur at different locations

2. - E1A05

What is the maximum power output permitted on the 60 meter band?

Select	Answer
A	50 watts PEP effective radiated power relative to an isotropic radiator
B	100 watts PEP effective radiated power relative to the gain of a half-wave dipole
C	100 watts PEP effective radiated power relative to an isotropic radiator
D	50 watts PEP effective radiated power relative to a dipole

3. - E1B01

Which of the following constitutes a spurious emission?

Select	Answer
A	An amateur station transmission made without the proper call sign identification
B	Any transmitted signal that unintentionally interferes with another licensed radio station
C	A signal transmitted to prevent its detection by any station other than the intended recipient
D	An emission outside the signal's necessary bandwidth that can be reduced or eliminated without affecting the information transmitted

4. - E1C10

What is the permitted mean power of any spurious emission relative to the mean power of the fundamental emission from a station transmitter or external RF amplifier installed after January 1, 2003 and transmitting on a frequency below 30 MHz?

Select	Answer
A	At least 43 dB below
B	At least 73 dB below
C	At least 63 dB below
D	At least 53 dB below

5. - E1D04

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

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

6. - E1E09

What may be the penalty for a VE who fraudulently administers or certifies an examination?

Select	Answer
A	Revocation of the VE's amateur station license grant and the suspension of the VE's amateur operator license grant
B	A fine of up to $1000 per occurrence
C	All these choices are correct
D	A sentence of up to one year in prison

7. - E1F02

What privileges are authorized in the U.S. to persons holding an amateur service license granted by the government of Canada?

Select	Answer
A	The operating terms and conditions of the Canadian amateur service license, not to exceed U.S. Amateur Extra Class license privileges
B	All privileges of the Amateur Extra Class license
C	None, they must obtain a U.S. license
D	Full privileges, up to and including those of the Amateur Extra Class license, on the 80, 40, 20, 15, and 10 meter bands

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	Upper sideband on the uplink becomes lower sideband on the downlink, and vice versa
C	Doppler shift is reduced because the uplink and downlink shifts are in opposite directions
D	All these choices are correct

9. - E2B02

How many horizontal lines make up a fast-scan (NTSC) television frame?

Select	Answer
A	60
B	1080
C	30
D	525

10. - E2C12

What technique do individual nodes use to form a mesh network?

Select	Answer
A	Custom code plugs for the local trunking systems
B	Acting as store-and-forward digipeaters
C	Forward error correction and Viterbi codes
D	Discovery and link establishment protocols

11. - E2D08

What type of packet frame is used to transmit APRS beacon data?

Select	Answer
A	Connect
B	Unnumbered Information
C	Acknowledgement
D	Disconnect

12. - E2E08

Which of the following HF digital modes can be used to transfer binary files?

Select	Answer
A	RTTY
B	AMTOR
C	PACTOR
D	Hellschreiber

13. - E3A03

When scheduling EME contacts, which of these conditions will generally result in the least path loss?

Select	Answer
A	When the moon is at apogee
B	When the MUF is above 30 MHz
C	When the moon is at perigee
D	When the moon is full

14. - E3B12

What is the primary characteristic of chordal hop propagation?

Select	Answer
A	Propagation across the geomagnetic equator
B	Propagation away from the great circle bearing between stations
C	Signals reflected back toward the transmitting station
D	Successive ionospheric refractions without an intermediate reflection from the ground

15. - E3C12

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

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

16. - E4A03

Which of the following test instruments is used to display spurious signals and/or intermodulation distortion products generated by an SSB transmitter?

Select	Answer
A	A logic analyzer
B	A wattmeter
C	A spectrum analyzer
D	A time-domain reflectometer

17. - E4B07

What do the subscripts of S parameters represent?

Select	Answer
A	Frequency order of the measurements
B	The relative time between measurements
C	The port or ports at which measurements are made
D	Relative quality of the data

18. - E4C06

A CW receiver with the AGC off has an equivalent input noise power density of -174 dBm/Hz. What would be the level of an unmodulated carrier input to this receiver that would yield an audio output SNR of 0 dB in a 400 Hz noise bandwidth?

Select	Answer
A	-155 dBm
B	-148 dBm
C	-164 dBm
D	-174 dBm

19. - E4D07

Which of the following reduces the likelihood of receiver desensitization?

Select	Answer
A	Switch from fast AGC to slow AGC
B	Decrease the RF bandwidth of the receiver
C	Raise the receiver IF frequency
D	Increase the receiver front end gain

20. - E4E03

Which of the following signals might a receiver noise blanker be able to remove from desired signals?

Select	Answer
A	Signals that appear at one IF but not another
B	Signals that have a sharply peaked frequency distribution
C	Signals that are constant at all IF levels
D	Signals that appear across a wide bandwidth

21. - E5A12

What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 3.7 MHz and a Q of 118?

Select	Answer
A	31.4 kHz
B	218.3 kHz
C	436.6 kHz
D	15.7 kHz

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

23. - E5C08

What coordinate system is often used to display the phase angle of a circuit containing resistance, inductive and/or capacitive reactance?

Select	Answer
A	Maidenhead grid
B	Faraday grid
C	Elliptical coordinates
D	Polar coordinates

24. - E5D09

What happens to reactive power in an AC circuit that has both ideal inductors and ideal capacitors?

Select	Answer
A	It is dissipated as heat in the circuit
B	It is dissipated as kinetic energy in the circuit
C	It is repeatedly exchanged between the associated magnetic and electric fields, but is not dissipated
D	It is dissipated in the formation of inductive and capacitive fields

25. - E6A03

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

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

26. - E6B03

What type of bias is required for an LED to emit light?

Select	Answer
A	Reverse bias
B	Inductive bias
C	Zero bias
D	Forward bias

27. - E6C10

In Figure E6-3, what is the schematic symbol for a NOR gate?

Select	Answer
A	3
B	4
C	1
D	2

28. - E6D12

What is inductor saturation?

Select	Answer
A	Adjacent inductors become over-coupled
B	The ability of the inductor's core to store magnetic energy has been exceeded
C	The inductor windings are over-coupled
D	The inductor's voltage rating is exceeded causing a flashover

29. - E6E03

Which of the following materials is likely to provide the highest frequency of operation when used in MMICs?

Select	Answer
A	Silicon nitride
B	Silicon
C	Silicon dioxide
D	Gallium nitride

30. - E6F01

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

Select	Answer
A	Protons
B	Electrons
C	Photons
D	Holes

31. - E7A10

What is a truth table?

Select	Answer
A	A table of logic symbols that indicate the logic states of an op-amp
B	A list of inputs and corresponding outputs for a digital device
C	A table of logic symbols that indicate the high logic states of an op-amp
D	A diagram showing logic states when the digital device output is true

32. - E7B14

Why are switching amplifiers more efficient than linear amplifiers?

Select	Answer
A	The power transistor is at saturation or cutoff most of the time
B	Switching amplifiers operate at higher voltages
C	Linear amplifiers have high gain resulting in higher harmonic content
D	Switching amplifiers use push-pull circuits

33. - E7C05

Which filter type is described as having ripple in the passband and a sharp cutoff?

Select	Answer
A	An active LC filter
B	A Butterworth filter
C	A Chebyshev filter
D	A passive op-amp filter

34. - E7D08

What type of circuit is shown in Figure E7-2?

Select	Answer
A	Monostable multivibrator
B	Grounded emitter amplifier
C	Switching voltage regulator
D	Linear voltage regulator

35. - E7E01

Which of the following can be used to generate FM phone emissions?

Select	Answer
A	A balanced modulator on the audio amplifier
B	A reactance modulator on the final amplifier
C	A reactance modulator on the oscillator
D	A balanced modulator on the oscillator

36. - E7F09

Why is an anti-aliasing digital filter required in a digital decimator?

Select	Answer
A	It removes high-frequency signal components that would otherwise be reproduced as lower frequency components
B	It peaks the response of the decimator, improving bandwidth
C	It notches out the sampling frequency to avoid sampling errors
D	It removes low-frequency signal components to eliminate the need for DC restoration

37. - E7G12

What is an operational amplifier?

Select	Answer
A	A digital audio amplifier whose characteristics are determined by components external to the amplifier
B	A high-gain, direct-coupled differential amplifier with very high input impedance and very low output impedance
C	A RF amplifier used in the UHF and microwave regions
D	An amplifier used to increase the average output of frequency modulated amateur signals to the legal limit

38. - E7H02

What is a microphonic?

Select	Answer
A	An IC used for amplifying microphone signals
B	Changes in oscillator frequency due to mechanical vibration
C	Excess loading of the microphone by an oscillator
D	Distortion caused by RF pickup on the microphone cable

39. - E8A08

Why would a direct or flash conversion analog-to-digital converter be useful for a software defined radio?

Select	Answer
A	Immunity to out-of-sequence coding reduces spurious responses
B	Very low power consumption decreases frequency drift
C	All these choices are correct
D	Very high speed allows digitizing high frequencies

40. - E8B02

How does the modulation index of a phase-modulated emission vary with RF carrier frequency?

Select	Answer
A	It does not depend on the RF carrier frequency
B	It varies with the square root of the RF carrier frequency
C	It increases as the RF carrier frequency increases
D	It decreases as the RF carrier frequency increases

41. - E8C12

What factors affect the bandwidth of a transmitted CW signal?

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

42. - E8D08

What parameter evaluates distortion of an AFSK signal caused by excessive input audio levels?

Select	Answer
A	Intermodulation Distortion (IMD)
B	Repeat Request Rate (RRR)
C	Signal-to-noise ratio
D	Baud rate

43. - E9A04

Which of the following factors affect the feed point impedance of an antenna?

Select	Answer
A	The settings of an antenna tuner at the transmitter
B	Antenna height
C	The input power level
D	Transmission line length

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

45. - E9C07

What is the approximate feed point impedance at the center of a two-wire folded dipole antenna?

Select	Answer
A	450 ohms
B	72 ohms
C	50 ohms
D	300 ohms

46. - E9D11

Which of the following conductors would be best for minimizing losses in a station's RF ground system?

Select	Answer
A	Wide flat copper strap
B	Stranded wire
C	Solid wire
D	Resistive wire, such as spark plug wire

47. - E9E11

What is the primary purpose of phasing lines when used with an antenna having multiple driven elements?

Select	Answer
A	It allows single-band antennas to operate on other bands
B	It creates a low-angle radiation pattern
C	It ensures that each driven element operates in concert with the others to create the desired antenna pattern
D	It prevents reflected power from traveling back down the feed line and causing harmonic radiation from the transmitter

48. - E9F11

What impedance does a 1/8-wavelength transmission line present to a generator when the line is open at the far end?

Select	Answer
A	The same as the characteristic impedance of the line
B	An inductive reactance
C	Infinite
D	A capacitive reactance

49. - E9G07

On the Smith chart shown in Figure E9-3, what is the only straight line shown?

Select	Answer
A	The reactance axis
B	The voltage axis
C	The current axis
D	The resistance axis

50. - E9H11

What feature of a cardioid pattern antenna makes it useful for direction finding?

Select	Answer
A	Broadband response
B	High radiation angle
C	A very sharp single null
D	A very sharp peak

Figure E6-3

Figure E7-2

Figure E9-3