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

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1. - E0A09

Which insulating material commonly used as a thermal conductor for some types of electronic devices is extremely toxic if broken or crushed and the particles are accidentally inhaled?

Select	Answer
A	Mica
B	Zinc oxide
C	Uranium Hexafluoride
D	Beryllium Oxide

2. - E1A10

If an amateur station is installed aboard a ship or aircraft, what condition must be met before the station is operated?

Select	Answer
A	The amateur station operator must agree not to transmit when the main radio of the ship or aircraft is in use
B	Its operation must be approved by the master of the ship or the pilot in command of the aircraft
C	The amateur operator must have an FCC Marine or Aircraft endorsement on his or her amateur license
D	The amateur station must have a power supply that is completely independent of the main ship or aircraft power supply

3. - E1B11

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

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

4. - E1C09

What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?

Select	Answer
A	2.0
B	0.5
C	3.0
D	1.0

5. - E1D08

Which VHF amateur bands have frequencies authorized for space stations?

Select	Answer
A	2 meters
B	6 meters, 2 meters, and 1.25 meters
C	2 meters and 1.25 meters
D	6 meters and 2 meters

6. - E1E06

Who is responsible for the proper conduct and necessary supervision during an amateur operator license examination session?

Select	Answer
A	Each administering VE
B	The FCC
C	The VE session manager
D	The VEC coordinating the session

7. - E1F06

Under what circumstances might the FCC issue a Special Temporary Authority (STA) to an amateur station?

Select	Answer
A	To provide temporary operation while awaiting normal licensing
B	To provide additional spectrum for personal use
C	To provide for experimental amateur communications
D	To allow regular operation on Land Mobile channels

8. - E2A13

Which of the following techniques is normally used by low Earth orbiting digital satellites to relay messages around the world?

Select	Answer
A	Node hopping
B	Digipeating
C	Store-and-forward
D	Multi-satellite relaying

9. - E2B02

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

Select	Answer
A	60
B	525
C	30
D	1080

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	HF frequencies where digital communications are permitted
C	The 60 meter band channel centered on 5373 kHz
D	Frequencies shared with various unlicensed wireless data services

11. - E2D05

What is one advantage of the JT65 mode?

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

12. - E2E11

What is the difference between direct FSK and audio FSK?

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

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	500 miles, if the moon is at perigee
C	2000 miles, if the moon is at apogee
D	12,000 miles, if the moon is visible by both stations

14. - E3B02

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

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

15. - E3C10

What does the 304A solar parameter measure?

Select	Answer
A	The ratio of x-ray flux to radio flux, correlated to sunspot number
B	The solar emission at 304 GHz, correlated to x-ray flare levels
C	UV emissions at 304 angstroms, correlated to the solar flux index
D	The solar wind velocity at 304 degrees from the solar equator, correlated to solar activity

16. - E4A05

What is the purpose of the prescaler function on a frequency counter?

Select	Answer
A	It amplifies low-level signals for more accurate counting
B	It multiplies a higher frequency signal so a low-frequency counter can display the operating frequency
C	It prevents oscillation in a low-frequency counter circuit
D	It divides a higher frequency signal so a low-frequency counter can display the input frequency

17. - E4B10

Which of the following methods measures intermodulation distortion in an SSB transmitter?

Select	Answer
A	Modulate the transmitter using two RF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
B	Modulate the transmitter using two RF signals having harmonically related frequencies and observe the RF output with a logic analyzer
C	Modulate the transmitter using two AF signals having harmonically related frequencies and observe the RF output with a peak reading wattmeter
D	Modulate the transmitter using two AF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer

18. - E4C07

What does the MDS of a receiver represent?

Select	Answer
A	The meter display sensitivity
B	The maximum detectable spectrum
C	The multiplex distortion stability
D	The minimum discernible signal

19. - E4D05

What transmitter frequencies would cause an intermodulation-product signal in a receiver tuned to 146.70 MHz when a nearby station transmits on 146.52 MHz?

Select	Answer
A	146.88 MHz and 146.34 MHz
B	146.34 MHz and 146.61 MHz
C	173.35 MHz and 139.40 MHz
D	146.10 MHz and 147.30 MHz

20. - E4E07

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

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

21. - E5A01

What can cause the voltage across reactances in a series RLC circuit to be higher than the voltage applied to the entire circuit?

Select	Answer
A	Resonance
B	Conductance
C	Capacitance
D	Resistance

22. - E5B09

What is the relationship between the AC current through a capacitor and the voltage across a capacitor?

Select	Answer
A	Voltage and current are in phase
B	Current leads voltage by 90 degrees
C	Voltage leads current by 90 degrees
D	Voltage and current are 180 degrees out of phase

23. - E5C10

Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 400-ohm resistor and a 38-picofarad capacitor at 14 MHz?

Select	Answer
A	Point 2
B	Point 4
C	Point 5
D	Point 6

24. - E5D11

What is the power factor of an RL circuit having a 60-degree phase angle between the voltage and the current?

Select	Answer
A	1.73
B	0.866
C	1.414
D	0.5

25. - E6A12

Why do many MOSFET devices have internally connected Zener diodes on the gates?

Select	Answer
A	To provide a voltage reference for the correct amount of reverse-bias gate voltage
B	To reduce the chance of static damage to the gate
C	To protect the substrate from excessive voltages
D	To keep the gate voltage within specifications and prevent the device from overheating

26. - E6B02

What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

Select	Answer
A	Longer carrier retention time
B	More constant reverse avalanche voltage
C	Much higher reverse voltage breakdown
D	Less forward voltage drop

27. - E6C10

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

Select	Answer
A	3
B	2
C	1
D	4

28. - E6D03

Which of the following is an aspect of the piezoelectric effect?

Select	Answer
A	Mechanical deformation of material by the application of a magnetic field
B	Mechanical deformation of material by the application of a voltage
C	Generation of electrical energy in the presence of light
D	Increased conductivity in the presence of light

29. - E6E07

What type of transmission line is used for connections to MMICs?

Select	Answer
A	Parallel wire
B	Microstrip
C	Miniature coax
D	Circular waveguide

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 output RF power divided by the input DC power
C	The relative fraction of light that is converted to current
D	Cost per kilowatt-hour generated

31. - E7A06

What is a characteristic of a monostable multivibrator?

Select	Answer
A	It maintains a constant output voltage, regardless of variations in the input voltage
B	It switches momentarily to the opposite binary state and then returns to its original state after a set time
C	It stores one bit of data in either a 0 or 1 state
D	It produces a continuous square wave oscillating between 1 and 0

32. - E7B03

Which of the following components form the output of a class D amplifier circuit?

Select	Answer
A	A high-pass filter to compensate for low gain at low frequencies
B	A low-pass filter to remove switching signal components
C	A temperature compensating load resistor to improve linearity
D	A matched load resistor to prevent damage by switching transients

33. - E7C03

What advantage does a series-L Pi-L-network have over a series-L Pi-network for impedance matching between the final amplifier of a vacuum-tube transmitter and an antenna?

Select	Answer
A	Greater harmonic suppression
B	Does not require a capacitor
C	Greater transformation range
D	Higher efficiency

34. - E7D04

Which of the following types of linear voltage regulator usually make the most efficient use of the primary power source?

Select	Answer
A	A shunt regulator
B	A series regulator
C	A shunt current source
D	A series current source

35. - E7E04

What is one way a single-sideband phone signal can be generated?

Select	Answer
A	By using a reactance modulator followed by a mixer
B	By driving a product detector with a DSB signal
C	By using a loop modulator followed by a mixer
D	By using a balanced modulator followed by a filter

36. - E7F14

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

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

37. - E7G07

What magnitude of voltage gain can be expected from the circuit in Figure E73 when R1 is 10 ohms and RF is 470 ohms?

Select	Answer
A	94
B	47
C	24
D	0.21

38. - E7H06

Which of the following oscillator circuits are commonly used in VFOs?

Select	Answer
A	Armstrong and deForest
B	Negative feedback and balanced feedback
C	Colpitts and Hartley
D	Pierce and Zener

39. - E8A07

What determines the PEP-to-average power ratio of a single-sideband phone signal?

Select	Answer
A	Amplifier gain
B	The frequency of the modulating signal
C	Speech characteristics
D	The degree of carrier suppression

40. - E8B02

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

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

41. - E8C08

How does ARQ accomplish error correction?

Select	Answer
A	Special polynomial codes provide automatic correction
B	If errors are detected, redundant data is substituted
C	If errors are detected, a retransmission is requested
D	Special binary codes provide automatic correction

42. - E8D07

What is a common cause of overmodulation of AFSK signals?

Select	Answer
A	Ground loops
B	Excessive numbers of retries
C	Excessive transmit audio levels
D	Bit errors in the modem

43. - E9A02

What is the effective radiated power relative to a dipole of a repeater station with 150 watts transmitter power output, 2 dB feed line loss, 2.2 dB duplexer loss, and 7 dBd antenna gain?

Select	Answer
A	78.7 watts
B	1977 watts
C	420 watts
D	286 watts

44. - E9B02

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

Select	Answer
A	14 dB
B	24 dB
C	18 dB
D	36 dB

45. - E9C10

Which of the following describes a Zepp antenna?

Select	Answer
A	A vertical array capable of quickly changing the direction of maximum radiation by changing phasing lines
B	An end-fed dipole antenna
C	An omni-directional antenna commonly used for satellite communications
D	A dipole constructed from zip cord

46. - E9D09

What is the function of a loading coil used as part of an HF mobile antenna?

Select	Answer
A	To lower the Q
B	To increase the SWR bandwidth
C	To cancel capacitive reactance
D	To lower the losses

47. - E9E04

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

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

48. - E9F09

What is the approximate physical length of a foam polyethylene dielectric coaxial transmission line that is electrically 1/4 wavelength long at 7.2 MHz?

Select	Answer
A	5.2 meters
B	6.9 meters
C	10.4 meters
D	8.3 meters

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 resistance axis
C	The voltage axis
D	The current axis

50. - E9H06

What is the triangulation method of direction finding?

Select	Answer
A	The geometric angles of sky waves from the source are used to determine its position
B	A fixed receiving station plots three headings to the signal source
C	A fixed receiving station uses three different antennas to plot the location of the signal source
D	Antenna headings from several different receiving locations are used to locate the signal source

Figure E5-1

Figure E6-3

Figure E9-1

Figure E9-3