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

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1. - E0A11

Which of the following injuries can result from using high-power UHF or microwave transmitters?

Select	Answer
A	Blood clotting from the intense magnetic field
B	Hearing loss caused by high voltage corona discharge
C	Localized heating of the body from RF exposure in excess of the MPE limits
D	Ingestion of ozone gas from the cooling system

2. - E1A03

What is the maximum legal carrier frequency on the 20 meter band for transmitting USB AFSK digital signals having a 1 kHz bandwidth?

Select	Answer
A	14.149 MHz
B	14.070 MHz
C	14.349 MHz
D	14.100 MHz

3. - E1B11

What does PRB-1 require of regulations affecting amateur radio?

Select	Answer
A	Use of wireless devices in a vehicle is exempt from regulation
B	No limitations may be placed on antenna size or placement
C	Reasonable accommodations of amateur radio must be made
D	Amateur radio operations must be permitted in any private residence

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 73 dB below
B	At least 53 dB below
C	At least 63 dB below
D	At least 43 dB below

5. - E1D03

What is a space telecommand station?

Select	Answer
A	An amateur station that transmits communications to initiate, modify or terminate functions of a space station
B	An amateur station located in a satellite or a balloon more than 50 kilometers above the surface of the Earth
C	An amateur station located on the surface of the Earth for communication with other Earth stations by means of Earth satellites
D	An amateur station that receives telemetry from a satellite or balloon more than 50 kilometers above the surface of the Earth

6. - E1E08

To which of the following examinees may a VE not administer an examination?

Select	Answer
A	Friends of the VE
B	Employees of the VE
C	All these choices are correct
D	Relatives of the VE as listed in the FCC rules

7. - E1F08

Which of the following types of amateur station communications are prohibited?

Select	Answer
A	Communications that have religious content
B	Communications in a language other than English
C	Communications that have political content, except as allowed by the Fairness Doctrine
D	Communications transmitted for hire or material compensation, except as otherwise provided in the rules

8. - E2A09

What do the terms L band and S band specify regarding satellite communications?

Select	Answer
A	Which sideband to use
B	The 23 centimeter and 13 centimeter bands
C	The 2 meter and 70 centimeter bands
D	FM and Digital Store-and-Forward systems

9. - E2B06

What is vestigial sideband modulation?

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

10. - E2C02

Which of the following best describes the term self-spotting? in connection with HF contest operating?

Select	Answer
A	The often-prohibited practice of posting one's own call sign and frequency on a spotting network
B	An automatic method for rapidly zero beating or tuning to a station's frequency before calling that station
C	The acceptable practice of manually posting the call signs of stations on a spotting network
D	A manual technique for rapidly zero beating or tuning to a station's frequency before calling that station

11. - E2D04

What technology is used to track, in real time, balloons carrying amateur radio transmitters?

Select	Answer
A	Doppler shift of beacon signals
B	Ultrasonics
C	Bandwidth compressed LORAN
D	APRS

12. - E2E11

What is the difference between direct FSK and audio FSK?

Select	Answer
A	Direct FSK occupies less bandwidth
B	Only direct FSK can be decoded by computer
C	Direct FSK applies the data signal to the transmitter VFO, while AFSK transmits tones via phone
D	Direct FSK can transmit faster baud rates

13. - E3A01

What is the approximate maximum separation measured along the surface of the Earth between two stations communicating by EME?

Select	Answer
A	5000 miles, if the moon is at perigee
B	2000 miles, if the moon is at apogee
C	500 miles, if the moon is at perigee
D	12,000 miles, if the moon is visible by both stations

14. - E3B10

Why is chordal hop propagation desirable?

Select	Answer
A	The MUF for chordal hop propagation is much lower than for normal skip propagation
B	Signals travel faster along ionospheric chords
C	Atmospheric noise is lower in the direction of chordal hop propagation
D	The signal experiences less loss compared to multi-hop using Earth as a reflector

15. - E3C08

What does the space weather term G5 mean?

Select	Answer
A	Moderate solar wind
B	Waning sunspot numbers
C	An extreme geomagnetic storm
D	Very low solar activity

16. - E4A08

Which of the following measures SWR?

Select	Answer
A	A Q meter
B	An antenna analyzer
C	An ohmmeter
D	A spectrum analyzer

17. - E4B05

What three test loads are used to calibrate an RF vector network analyzer?

Select	Answer
A	Short circuit, open circuit, and resonant circuit
B	50 ohms through 1/8 wavelength, 1/4 wavelength, and 1/2 wavelength of coaxial cable
C	Short circuit, open circuit, and 50 ohms
D	50 ohms, 75 ohms, and 90 ohms

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	-148 dBm
B	-164 dBm
C	-174 dBm
D	-155 dBm

19. - E4D12

What is the term for the reduction in receiver sensitivity caused by a strong signal near the received frequency?

Select	Answer
A	Desensitization
B	Squelch gain rollback
C	Quieting
D	Cross-modulation interference

20. - E4E06

What is one type of electrical interference that might be caused by a nearby personal computer?

Select	Answer
A	The appearance of unstable modulated or unmodulated signals at specific frequencies
B	A clicking noise at intervals of a few seconds
C	A loud AC hum in the audio output of your station receiver
D	A whining type noise that continually pulses off and on

21. - E5A13

What is an effect of increasing Q in a series resonant circuit?

Select	Answer
A	Fewer components are needed for the same performance
B	Internal voltages increase
C	Parasitic effects are minimized
D	Phase shift can become uncontrolled

22. - E5B12

What is admittance?

Select	Answer
A	The turns ratio of a transformer
B	The inverse of impedance
C	The inverse of Q factor
D	The term for the gain of a field effect transistor

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	Near field diagram
C	Venn diagram
D	Phasor diagram

24. - E5D12

How many watts are consumed in a circuit having a power factor of 0.2 if the input is 100 VAC at 4 amperes?

Select	Answer
A	400 watts
B	2000 watts
C	80 watts
D	50 watts

25. - E6A02

Which of the following semiconductor materials contains excess free electrons?

Select	Answer
A	Insulated gate
B	N-type
C	P-type
D	Bipolar

26. - E6B10

In Figure E6-2, what is the schematic symbol for a light-emitting diode?

Select	Answer
A	6
B	7
C	5
D	1

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. - E6D11

Which type of core material decreases inductance when inserted into a coil?

Select	Answer
A	Powdered iron
B	Brass
C	Ferrite
D	Ceramic

29. - E6E06

What characteristics of the MMIC make it a popular choice for VHF through microwave circuits?

Select	Answer
A	Nearly infinite gain, very high input impedance, and very low output impedance
B	Controlled gain, low noise figure, and constant input and output impedance over the specified frequency range
C	The ability to retrieve information from a single signal even in the presence of other strong signals
D	Plate current that is controlled by a control grid

30. - E6F09

What is the efficiency of a photovoltaic cell?

Select	Answer
A	The open-circuit voltage divided by the short-circuit current under full illumination
B	The relative fraction of light that is converted to current
C	The output RF power divided by the input DC power
D	Cost per kilowatt-hour generated

31. - E7A11

What type of logic defines "1" as a high voltage?

Select	Answer
A	Assertive Logic
B	Reverse Logic
C	Negative logic
D	Positive Logic

32. - E7B08

How can an RF power amplifier be neutralized?

Select	Answer
A	By reducing the driving power
B	By increasing the driving power
C	By feeding an in-phase component of the output back to the input
D	By feeding a 180-degree out-of-phase portion of the output back to the input

33. - E7C05

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

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

34. - E7D07

What is the purpose of C2 in the circuit shown in Figure E7-2?

Select	Answer
A	To provide fixed DC bias for Q1
B	To self-resonate at the hum frequency
C	It bypasses rectifier output ripple around D1
D	It is a brute force filter for the output

35. - E7E03

What is a frequency discriminator stage in a FM receiver?

Select	Answer
A	An FM generator circuit
B	A circuit for filtering two closely adjacent signals
C	An automatic band-switching circuit
D	A circuit for detecting FM signals

36. - E7F03

What type of digital signal processing filter is used to generate an SSB signal?

Select	Answer
A	An adaptive filter
B	An elliptical filter
C	A Hilbert-transform filter
D	A notch filter

37. - E7G11

What absolute voltage gain can be expected from the circuit in Figure E7-3 when R1 is 3300 ohms and RF is 47 kilohms?

Select	Answer
A	0.07
B	7
C	14
D	28

38. - E7H01

What are three oscillator circuits used in amateur radio equipment?

Select	Answer
A	Taft, Pierce and negative feedback
B	Colpitts, Hartley and Pierce
C	Pierce, Fenner and Beane
D	Taft, Hartley and Pierce

39. - E8A10

What is the purpose of a low-pass filter used in conjunction with a digital-to-analog converter?

Select	Answer
A	Improve accuracy by removing out-of-sequence codes from the input
B	Lower the input bandwidth to increase the effective resolution
C	All these choices are correct
D	Remove harmonics from the output caused by the discrete analog levels generated

40. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

Select	Answer
A	A bandwidth compression technique using Fourier transforms
B	A frequency modulation technique that uses non-harmonically related frequencies
C	A digital modulation technique using subcarriers at frequencies chosen to avoid intersymbol interference
D	A digital mode for narrow-band, slow-speed transmissions

41. - E8C01

How is Forward Error Correction implemented?

Select	Answer
A	By transmitting a special algorithm to the receiving station along with the data characters
B	By varying the frequency shift of the transmitted signal according to a predefined algorithm
C	By transmitting extra data that may be used to detect and correct transmission errors
D	By the receiving station repeating each block of three data characters

42. - E8D08

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

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

43. - E9A07

What is the effective isotropic radiated power of a repeater station with 200 watts transmitter power output, 2 dB feed line loss, 2.8 dB duplexer loss, 1.2 dB circulator loss, and 7 dBi antenna gain?

Select	Answer
A	159 watts
B	632 watts
C	63.2 watts
D	252 watts

44. - E9B03

In the antenna radiation pattern shown in Figure E9-1, what is the front-to-side ratio?

Select	Answer
A	14 dB
B	24 dB
C	12 dB
D	18 dB

45. - E9C04

What happens to the radiation pattern of an unterminated long wire antenna as the wire length is increased?

Select	Answer
A	The front-to-back ratio decreases
B	The vertical angle increases
C	The lobes become more perpendicular to the wire
D	The lobes align more in the direction of the wire

46. - E9D10

What happens to feed-point impedance at the base of a fixed length HF mobile antenna when operated below its resonant frequency?

Select	Answer
A	The radiation resistance decreases and the capacitive reactance increases
B	The radiation resistance decreases and the capacitive reactance decreases
C	The radiation resistance increases and the capacitive reactance decreases
D	The radiation resistance increases and the capacitive reactance increases

47. - E9E03

What is the name of the matching system that uses a section of transmission line connected in parallel with the feed line at or near the feed point?

Select	Answer
A	The stub match
B	The gamma match
C	The omega match
D	The delta match

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

49. - E9G08

What is the process of normalization with regard to a Smith chart?

Select	Answer
A	Reassigning resistance values with regard to the reactance axis
B	Reassigning reactance values with regard to the resistance axis
C	Reassigning impedance values with regard to the prime center
D	Reassigning prime center with regard to the reactance axis

50. - E9H09

What is a Pennant antenna?

Select	Answer
A	A small, vertically oriented receiving antenna consisting of a triangular loop terminated in approximately 900 ohms
B	A stealth antenna built to look like a flagpole
C	A four-element, high-gain vertical array invented by George Pennant
D	A form of rhombic antenna terminated in a variable capacitor to provide frequency diversity

Figure E6-2

Figure E6-3

Figure E7-2

Figure E7-3

Figure E9-1