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

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1. - E0A08

What does SAR measure?

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

2. - E1A06

Where must the carrier frequency of a CW signal be set to comply with FCC rules for 60 meter operation?

Select	Answer
A	On any frequency where the signal's sidebands are within the channel
B	At the center frequency of the channel
C	At the lowest frequency of the channel
D	At the highest frequency of the channel

3. - E1B07

To what type of regulations does PRB-1 apply?

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

4. - E1C03

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

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

5. - E1D09

Which UHF amateur bands have frequencies authorized for space stations?

Select	Answer
A	70 cm only
B	70 cm and 13 cm
C	33 cm and 13 cm
D	70 cm and 33 cm

6. - E1E11

What must the VE team do if an examinee scores a passing grade on all examination elements needed for an upgrade or new license?

Select	Answer
A	Issue the examinee the new or upgrade license
B	Three VEs must certify that the examinee is qualified for the license grant and that they have complied with the administering VE requirements
C	Photocopy all examination documents and forward them to the FCC for processing
D	All these choices are correct

7. - E1F11

Which of the following best describes one of the standards that must be met by an external RF power amplifier if it is to qualify for a grant of FCC certification?

Select	Answer
A	It must exhibit a gain of 0 dB or less over its full output range
B	It must be capable of external RF switching between its input and output networks
C	It must produce full legal output when driven by not more than 5 watts of mean RF input power
D	It must satisfy the FCC's spurious emission standards when operated at the lesser of 1500 watts or its full output power

8. - E2A05

What do the letters in a satellite's mode designator specify?

Select	Answer
A	Power limits for uplink and downlink transmissions
B	The polarization of uplink and downlink signals
C	The location of the ground control station
D	The uplink and downlink frequency ranges

9. - E2B12

What signals SSTV receiving software to begin a new picture line?

Select	Answer
A	Specific tone amplitudes
B	Elapsed time
C	Specific tone frequencies
D	A two-tone signal

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	A manual technique 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	An automatic method for rapidly zero beating or tuning to a station's frequency before calling that station

11. - E2D03

Which of the following digital modes is especially useful for EME communications?

Select	Answer
A	JT65
B	Olivia
C	MSK144
D	PACTOR III

12. - E2E02

What do the letters FEC mean as they relate to digital operation?

Select	Answer
A	Final Error Correction
B	First Error Correction
C	Forward Error Correction
D	Fatal Error Correction

13. - E3A08

When a meteor strikes the Earth's atmosphere, a cylindrical region of free electrons is formed at what layer of the ionosphere?

Select	Answer
A	The D layer
B	The F1 layer
C	The E layer
D	The F2 layer

14. - E3B06

Which of the following amateur bands most frequently provides long-path propagation?

Select	Answer
A	20 meters
B	10 meters
C	6 meters
D	80 meters

15. - E3C02

What is indicated by a rising A or K index?

Select	Answer
A	Increasing disruption of the geomagnetic field
B	Decreasing disruption of the geomagnetic field
C	Higher levels of solar UV radiation
D	An increase in the critical frequency

16. - E4A02

Which of the following parameters does a spectrum analyzer display on the vertical and horizontal axes?

Select	Answer
A	RF amplitude and time
B	RF amplitude and frequency
C	SWR and time
D	SWR and frequency

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

18. - E4C01

What is an effect of excessive phase noise in a receiver's local oscillator?

Select	Answer
A	It can combine with strong signals on nearby frequencies to generate interference
B	It can affect the receiver's frequency calibration
C	It limits the receiver's ability to receive strong signals
D	It decreases receiver third-order intercept point

19. - E4D04

Which of the following may reduce or eliminate intermodulation interference in a repeater caused by another transmitter operating in close proximity?

Select	Answer
A	Utilizing a Class C final amplifier
B	A band-pass filter in the feed line between the transmitter and receiver
C	Utilizing a Class D final amplifier
D	A properly terminated circulator at the output of the repeater's transmitter

20. - E4E09

What undesirable effect can occur when using an IF noise blanker?

Select	Answer
A	The audio frequency bandwidth of the received signal might be compressed
B	Nearby signals may appear to be excessively wide even if they meet emission standards
C	Received audio in the speech range might have an echo effect
D	FM signals can no longer be demodulated

21. - E5A11

What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150?

Select	Answer
A	23.67 kHz
B	157.8 Hz
C	315.6 Hz
D	47.3 kHz

22. - E5B11

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 25 ohms, R is 100 ohms, and XL is 50 ohms?

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

23. - E5C09

When using rectangular coordinates to graph the impedance of a circuit, what do the axes represent?

Select	Answer
A	The X axis represents the phase angle and the Y axis represents the magnitude
B	The X axis represents the resistive component and the Y axis represents the reactive component
C	The X axis represents the magnitude and the Y axis represents the phase angle
D	The X axis represents the reactive component and the Y axis represents the resistive component

24. - E5D01

What is the result of skin effect?

Select	Answer
A	As frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface
B	Thermal effects on the surface of the conductor increase the impedance
C	Thermal effects on the surface of the conductor decrease the impedance
D	As frequency decreases, RF current flows in a thinner layer of the conductor, closer to the surface

25. - E6A02

Which of the following semiconductor materials contains excess free electrons?

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

26. - E6B07

What is the failure mechanism when a junction diode fails due to excessive current?

Select	Answer
A	Excessive inverse voltage
B	Charge carrier depletion
C	Excessive junction temperature
D	Insufficient forward voltage

27. - E6C07

What best describes a pull-up or pull-down resistor?

Select	Answer
A	A resistor in a keying circuit used to reduce key clicks
B	A resistor connected to an op-amp output that prevents signals from exceeding the power supply voltage
C	A resistor that ensures that an oscillator frequency does not drift
D	A resistor connected to the positive or negative supply line used to establish a voltage when an input or output is an open circuit

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

29. - E6E08

How is power supplied to the most common type of MMIC?

Select	Answer
A	MMICs require no operating bias
B	Directly to the bias voltage (VCC IN) lead
C	Through a capacitor and RF choke connected to the amplifier input lead
D	Through a resistor and/or RF choke connected to the amplifier output lead

30. - E6F02

What happens to the conductivity of a photoconductive material when light shines on it?

Select	Answer
A	It increases
B	It becomes unstable
C	It stays the same
D	It decreases

31. - E7A07

What logical operation does a NAND gate perform?

Select	Answer
A	It produces logic 0 at its output only when all inputs are logic 0
B	It produces logic 1 at its output only when all inputs are logic 1
C	It produces logic 0 at its output if some but not all inputs are logic 1
D	It produces logic 0 at its output only when all inputs are logic 1

32. - E7B16

What is the effect of intermodulation products in a linear power amplifier?

Select	Answer
A	All these choices are correct
B	Creation of parasitic oscillations
C	Transmission of spurious signals
D	Low efficiency

33. - E7C11

Which of the following describes a receiving filter's ability to reject signals occupying an adjacent channel?

Select	Answer
A	Passband ripple
B	Phase response
C	Shape factor
D	Noise factor

34. - E7D02

What is a characteristic of a switching electronic voltage regulator?

Select	Answer
A	The controlled device's duty cycle is changed to produce a constant average output voltage
B	The resistance of a control element is varied in direct proportion to the line voltage or load current
C	It is generally less efficient than a linear regulator
D	It gives a ramp voltage at its output

35. - E7E03

What is a frequency discriminator stage in a FM receiver?

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

36. - E7F01

What is meant by direct digital conversion as applied to software defined radios?

Select	Answer
A	A switching mixer is used to generate I and Q signals directly from the RF input
B	Incoming RF is digitized by an analog-to-digital converter without being mixed with a local oscillator signal
C	Software is converted from source code to object code during operation of the receiver
D	Incoming RF is converted to a control voltage for a voltage controlled oscillator

37. - E7G02

What is ringing in a filter?

Select	Answer
A	A reduction in high frequency response
B	An echo caused by a long time delay
C	Undesired oscillations added to the desired signal
D	Partial cancellation of the signal over a range of frequencies

38. - E7H12

Which of the following must be done to ensure that a crystal oscillator provides the frequency specified by the crystal manufacturer?

Select	Answer
A	Bias the crystal at a specified voltage
B	Provide the crystal with a specified parallel capacitance
C	Bias the crystal at a specified current
D	Provide the crystal with a specified parallel inductance

39. - E8A04

What is "dither" with respect to analog-to-digital converters?

Select	Answer
A	A method of decimation by randomly skipping samples
B	A small amount of noise added to the input signal to allow more precise representation of a signal over time
C	An abnormal condition where the converter cannot settle on a value to represent the signal
D	An error caused by irregular quantization step size

40. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

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

41. - E8C11

What is the relationship between symbol rate and baud?

Select	Answer
A	Symbol rate is only used for packet-based modes
B	Baud is only used for RTTY
C	They are the same
D	Baud is twice the symbol rate

42. - E8D08

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

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

43. - E9A03

What is the radiation resistance of an antenna?

Select	Answer
A	The combined losses of the antenna elements and feed line
B	The specific impedance of the antenna
C	The value of a resistance that would dissipate the same amount of power as that radiated from an antenna
D	The resistance in the atmosphere that an antenna must overcome to be able to radiate a signal

44. - E9B08

What is the far field of an antenna?

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

45. - E9C06

What is the effect of adding a terminating resistor to a rhombic antenna?

Select	Answer
A	It decreases the ground loss
B	It changes the radiation pattern from horizontal to vertical polarization
C	It changes the radiation pattern from bidirectional to unidirectional
D	It reflects the standing waves on the antenna elements back to the transmitter

46. - E9D06

What happens to the SWR bandwidth when one or more loading coils are used to resonate an electrically short antenna?

Select	Answer
A	It is decreased
B	It is unchanged if the loading coil is located at the feed point
C	It is increased
D	It is unchanged if the loading coil is located at a voltage maximum point

47. - E9E04

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

Select	Answer
A	To transform the antenna impedance to a higher value
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 cancel the inductive reactance of the matching network

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

49. - E9G10

What do the arcs on a Smith chart represent?

Select	Answer
A	Frequency
B	SWR
C	Points with constant resistance
D	Points with constant reactance

50. - E9H03

What is Receiving Directivity Factor (RDF)?

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