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	Uranium Hexafluoride
B	Beryllium Oxide
C	Zinc oxide
D	Mica

2. - E1A05

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

Select	Answer
A	100 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	50 watts PEP effective radiated power relative to a dipole
D	50 watts PEP effective radiated power relative to an isotropic radiator

3. - E1B10

What frequencies are authorized to an amateur station operating under RACES rules?

Select	Answer
A	Military Auxiliary Radio System (MARS) channels
B	Specific local government channels
C	Specific segments in the amateur service MF, HF, VHF and UHF bands
D	All amateur service frequencies authorized to the control operator

4. - E1C03

How do the control operator responsibilities of a station under automatic control differ from one under local control?

Select	Answer
A	Under automatic control the control operator is not required to be present at the control point
B	Under local control there is no control operator
C	Under automatic control there is no control operator
D	Under local control a control operator is not required to be present at a control point

5. - E1D04

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

Select	Answer
A	All these choices are correct
B	Call sign
C	The station's six-character Maidenhead grid locator
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	Warn the candidate that continued failure to comply will result in termination of the examination
B	Immediately terminate the candidate's examination
C	Immediately terminate everyone's examination and close the session
D	Allow the candidate to complete the examination, but invalidate the results

7. - E1F05

Amateur stations may not transmit in which of the following frequency segments if they are located in the contiguous 48 states and north of Line A?

Select	Answer
A	440 MHz - 450 MHz
B	53 MHz - 54 MHz
C	222 MHz - 223 MHz
D	420 MHz - 430 MHz

8. - E2A03

How is the signal inverted by an inverting linear transponder?

Select	Answer
A	The signal is reduced to I and Q components and the Q component is filtered out
B	The signal is passed through a mixer and the difference rather than the sum is transmitted
C	The signal is passed through a non-linear filter
D	The signal is detected and remodulated on the reverse sideband

9. - E2B02

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

Select	Answer
A	60
B	30
C	525
D	1080

10. - E2C08

Which of the following contacts may be confirmed through the U.S. QSL bureau system?

Select	Answer
A	Contacts between a U.S. station and a non-U.S. station
B	Repeater contacts between U.S. club members
C	Special event contacts between stations in the U.S.
D	Contacts using tactical call signs

11. - E2D02

Which of the following is a good technique for making meteor scatter contacts?

Select	Answer
A	All these choices are correct
B	15-second timed transmission sequences with stations alternating based on location
C	Short transmissions with rapidly repeated call signs and signal reports
D	Use of special digital modes

12. - E2E08

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

Select	Answer
A	AMTOR
B	RTTY
C	Hellschreiber
D	PACTOR

13. - E3A07

Atmospheric ducts capable of propagating microwave signals often form over what geographic feature?

Select	Answer
A	Mountain ranges
B	Urban areas
C	Bodies of water
D	Forests

14. - E3B07

What happens to linearly polarized radio waves that split into ordinary and extraordinary waves in the ionosphere?

Select	Answer
A	They are bent toward the magnetic poles
B	They become depolarized
C	They become elliptically polarized
D	They become phase locked

15. - E3C08

What does the space weather term G5 mean?

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

16. - E4A11

How should an antenna analyzer be connected when measuring antenna resonance and feed point impedance?

Select	Answer
A	Connect the antenna feed line directly to the analyzer's connector
B	Loosely couple the analyzer near the antenna base
C	Loosely couple the antenna and a dummy load to the analyzer
D	Connect the analyzer via a high-impedance transformer to the antenna

17. - E4B05

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

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

18. - E4C14

What transmit frequency might generate an image response signal in a receiver tuned to 14.300 MHz and that uses a 455 kHz IF frequency?

Select	Answer
A	14.755 MHz
B	15.210 MHz
C	13.845 MHz
D	14.445 MHz

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 difference in dB between the noise floor and the level of an incoming signal that will cause 1 dB of gain compression
C	The minimum difference in dB between two signals which produce third-order intermodulation products greater than the noise floor
D	The difference in dB between the noise floor and the third-order intercept point

20. - E4E02

Which of the following types of noise can often be reduced with a digital signal processing noise filter?

Select	Answer
A	Ignition noise
B	All these choices are correct
C	Power line noise
D	Broadband white noise

21. - E5A09

How is the Q of an RLC parallel resonant circuit calculated?

Select	Answer
A	Reactance of the inductance multiplied by the reactance of the capacitance
B	Reactance of either the inductance or capacitance divided by the resistance
C	Reactance of either the inductance or capacitance multiplied by the resistance
D	Resistance divided by the reactance of either the inductance or capacitance

22. - E5B08

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 100 ohms, R is 100 ohms, and XL is 75 ohms?

Select	Answer
A	14 degrees with the voltage lagging the current
B	14 degrees with the voltage leading the current
C	76 degrees with the voltage leading the current
D	76 degrees with the voltage lagging the current

23. - E5C04

What coordinate system is often used to display the resistive, inductive, and/or capacitive reactance components of impedance?

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

24. - E5D06

In what direction is the magnetic field oriented about a conductor in relation to the direction of electron flow?

Select	Answer
A	In a circle around the conductor
B	In a direction opposite to the current
C	In all directions; omni-directional
D	In the same direction as the current

25. - E6A11

In Figure E6-1, what is the schematic symbol for a P-channel junction FET?

Select	Answer
A	3
B	2
C	6
D	1

26. - E6B03

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

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

27. - E6C10

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

Select	Answer
A	4
B	1
C	3
D	2

28. - E6D04

Which materials are commonly used as a core in an inductor?

Select	Answer
A	Polystyrene and polyethylene
B	Teflon and Delrin
C	Cobalt and aluminum
D	Ferrite and brass

29. - E6E10

What advantage does surface-mount technology offer at RF compared to using through-hole components?

Select	Answer
A	Shorter circuit-board traces
B	All these choices are correct
C	Smaller circuit area
D	Components have less parasitic inductance and capacitance

30. - E6F06

Which of these materials is most commonly used to create photoconductive devices?

Select	Answer
A	A heavy metal
B	A crystalline semiconductor
C	A liquid semiconductor
D	An ordinary metal

31. - E7A09

What logical operation is performed by an exclusive NOR gate?

Select	Answer
A	It produces logic 0 at its output if only one input is logic 1
B	It produces logic 1 at its output only if all inputs are logic 1
C	It produces logic 0 at its output only if all inputs are logic 0
D	It produces logic 1 at its output if only one input is logic 1

32. - E7B06

Which of the following amplifier types reduces even-order harmonics?

Select	Answer
A	Push-push
B	Class C
C	Push-pull
D	Class AB

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

34. - E7D11

What is the function of the pass transistor in a linear voltage regulator circuit?

Select	Answer
A	Provides a stable input impedance over a wide range of source voltage
B	Permits a wide range of output voltage settings
C	Maintains nearly constant output voltage over a wide range of load current
D	Maintains nearly constant output impedance over a wide range of load current

35. - E7E06

Why is de-emphasis commonly used in FM communications receivers?

Select	Answer
A	To reduce impulse noise reception
B	For compatibility with transmitters using phase modulation
C	To remove third-order distortion products
D	For higher efficiency

36. - E7F06

What is the minimum number of bits required for an analog-to-digital converter to sample a signal with a range of 1 volt at a resolution of 1 millivolt?

Select	Answer
A	10 bits
B	4 bits
C	8 bits
D	6 bits

37. - E7G03

What is the typical input impedance of an op-amp?

Select	Answer
A	Very low
B	1000 ohms
C	100 ohms
D	Very high

38. - E7H06

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

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

39. - E8A08

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

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

40. - E8B04

What is the modulation index of an FM-phone signal having a maximum carrier deviation of plus or minus 6 kHz when modulated with a 2 kHz modulating frequency?

Select	Answer
A	1/3
B	6000
C	3
D	2000

41. - E8C10

How may data rate be increased without increasing bandwidth?

Select	Answer
A	Increasing analog-to-digital conversion resolution
B	Using forward error correction
C	Using a more efficient digital code
D	It is impossible

42. - E8D04

What is the primary effect of extremely short rise or fall time on a CW signal?

Select	Answer
A	Limits data speed
B	The generation of RF harmonics
C	The generation of key clicks
D	More difficult to copy

43. - E9A06

What is the effective radiated power relative to a dipole of a repeater station with 200 watts transmitter power output, 4 dB feed line loss, 3.2 dB duplexer loss, 0.8 dB circulator loss, and 10 dBd antenna gain?

Select	Answer
A	2000 watts
B	126 watts
C	317 watts
D	300 watts

44. - E9B08

What is the far field of an antenna?

Select	Answer
A	The region of the ionosphere where radiated power is not refracted
B	The region where radiated field strengths are constant
C	The region where radiated power dissipates over a specified time period
D	The region where the shape of the antenna pattern is independent of distance

45. - E9C03

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed in phase?

Select	Answer
A	A Figure-8 end-fire along the axis of the array
B	Omni-directional
C	Cardioid
D	A Figure-8 broadside to the axis of the array

46. - E9D09

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

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

47. - E9E08

What is a use for a Wilkinson divider?

Select	Answer
A	It is used to divide power equally between two 50-ohm loads while maintaining 50-ohm input impedance
B	It is used to feed low-impedance loads from a high-impedance source
C	It divides the operating frequency of a transmitter signal so it can be used on a lower frequency band
D	It is used to feed high-impedance antennas from a low-impedance source

48. - E9F12

What impedance does a 1/4-wavelength transmission line present to a generator when the line is open at the far end?

Select	Answer
A	The same as the input impedance to the generator
B	Very high impedance
C	The same as the characteristic impedance of the line
D	Very low impedance

49. - E9G02

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

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

50. - E9H03

What is Receiving Directivity Factor (RDF)?

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

Figure E6-1

Figure E6-3