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

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1. - E0A04

When evaluating a site with multiple transmitters operating at the same time, the operators and licensees of which transmitters are responsible for mitigating over-exposure situations?

Select	Answer
A	Only the most powerful transmitter
B	Each transmitter operating with a duty cycle greater than 50 percent
C	Each transmitter that produces 5 percent or more of its MPE limit in areas where the total MPE limit is exceeded.
D	Only commercial transmitters

2. - E1A04

With your transceiver displaying the carrier frequency of phone signals, you hear a DX station calling CQ on 3.601 MHz LSB. Is it legal to return the call using lower sideband on the same frequency?

Select	Answer
A	No, U.S. stations are not permitted to use phone emissions below 3.610 MHz
B	Yes, because the DX station initiated the contact
C	No, the sideband will extend beyond the edge of the phone band segment
D	Yes, because the displayed frequency is within the 75 meter phone band segment

3. - E1B09

Which amateur stations may be operated under RACES rules?

Select	Answer
A	Only those club stations licensed to Amateur Extra Class operators
B	Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served
C	Any FCC-licensed amateur station except a Technician Class
D	Any FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)

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	3.0
C	0.5
D	1.0

5. - E1D10

Which amateur stations are eligible to be telecommand stations of space stations (subject to the privileges of the class of operator license held by the control operator of the station)?

Select	Answer
A	Any amateur station designated by NASA
B	All these choices are correct
C	Any amateur station so designated by the ITU
D	Any amateur station so designated by the space station licensee

6. - E1E02

Who does Part 97 task with maintaining the pools of questions for all U.S. amateur license examinations?

Select	Answer
A	The VECs
B	The VEs
C	The FCC
D	The ARRL

7. - E1F08

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

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

8. - E2A02

Which of the following occurs when a satellite is using an inverting linear transponder?

Select	Answer
A	Doppler shift is reduced because the uplink and downlink shifts are in opposite directions
B	All these choices are correct
C	Upper sideband on the uplink becomes lower sideband on the downlink, and vice versa
D	Signal position in the band is reversed

9. - E2B07

What is the name of the signal component that carries color information in NTSC video?

Select	Answer
A	Hue
B	Chroma
C	Spectral intensity
D	Luminance

10. - E2C05

What is the function of a DX QSL Manager?

Select	Answer
A	To relay calls to and from a DX station
B	To run a net to allow many stations to contact a rare DX station
C	To handle the receiving and sending of confirmation cards for a DX station
D	To allocate frequencies for DXpeditions

11. - E2D09

What type of modulation is used for JT65 contacts?

Select	Answer
A	IEEE 802.11
B	PSK
C	Multi-tone AFSK
D	RTTY

12. - E2E09

Which of the following HF digital modes uses variable-length coding for bandwidth efficiency?

Select	Answer
A	PSK31
B	PACTOR
C	RTTY
D	MT63

13. - E3A11

What is a typical range for tropospheric propagation of microwave signals?

Select	Answer
A	1200 miles
B	2500 miles
C	10 miles to 50 miles
D	100 miles to 300 miles

14. - E3B06

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

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

15. - E3C10

What does the 304A solar parameter measure?

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

16. - E4A10

Which of the following displays multiple digital signal states simultaneously?

Select	Answer
A	Logic analyzer
B	Bit error rate tester
C	Network analyzer
D	Modulation monitor

17. - E4B04

Which S parameter represents input port return loss or reflection coefficient (equivalent to VSWR)?

Select	Answer
A	S21
B	S22
C	S12
D	S11

18. - E4C12

Which of the following has the largest effect on an SDR receiver's dynamic range?

Select	Answer
A	Anti-aliasing input filter bandwidth
B	RAM speed used for data storage
C	CPU register width in bits
D	Analog-to-digital converter sample width in bits

19. - E4D12

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

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

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 are constant at all IF levels
C	Signals that appear across a wide bandwidth
D	Signals that have a sharply peaked frequency distribution

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	Phase shift can become uncontrolled
C	Parasitic effects are minimized
D	Internal voltages increase

22. - E5B07

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 500 ohms, R is 1 kilohm, and XL is 250 ohms?

Select	Answer
A	14.0 degrees with the voltage lagging the current
B	14.0 degrees with the voltage leading the current
C	68.2 degrees with the voltage lagging the current
D	68.2 degrees with the voltage leading the current

23. - E5C11

Which point in Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and an 18-microhenry inductor at 3.505 MHz?

Select	Answer
A	Point 3
B	Point 7
C	Point 8
D	Point 1

24. - E5D07

How many watts are consumed in a circuit having a power factor of 0.71 if the apparent power is 500VA?

Select	Answer
A	704 W
B	355 W
C	1.42 mW
D	252 W

25. - E6A03

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

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

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	Less forward voltage drop
C	Much higher reverse voltage breakdown
D	More constant reverse avalanche voltage

27. - E6C05

What is an advantage of CMOS logic devices over TTL devices?

Select	Answer
A	Differential output capability
B	Immune to damage from static discharge
C	Lower power consumption
D	Lower distortion

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

29. - E6E11

What is a characteristic of DIP packaging used for integrated circuits?

Select	Answer
A	A total of two rows of connecting pins placed on opposite sides of the package (Dual In-line Package)
B	Low leakage doubly insulated package
C	Package mounts in a direct inverted position
D	Two chips in each package (Dual In Package)

30. - E6F09

What is the efficiency of a photovoltaic cell?

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

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 produces a continuous square wave oscillating between 1 and 0
C	It stores one bit of data in either a 0 or 1 state
D	It switches momentarily to the opposite binary state and then returns to its original state after a set time

32. - E7B15

What is one way to prevent thermal runaway in a bipolar transistor amplifier?

Select	Answer
A	All these choices are correct
B	Select transistors with high beta
C	Use a resistor in series with the emitter
D	Neutralization

33. - E7C08

Which of the following factors has the greatest effect on the bandwidth and response shape of a crystal ladder filter?

Select	Answer
A	The relative frequencies of the individual crystals
B	The amplitude of the signals passing through the filter
C	The gain of the RF stage preceding the filter
D	The DC voltage applied to the quartz crystal

34. - E7D08

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

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

35. - E7E09

What occurs when an excessive amount of signal energy reaches a mixer circuit?

Select	Answer
A	Mixer blanking occurs
B	Automatic limiting occurs
C	Spurious mixer products are generated
D	A beat frequency is generated

36. - E7F13

What is the function of taps in a digital signal processing filter?

Select	Answer
A	To reduce excess signal pressure levels
B	Select the point at which baseband signals are generated
C	Provide incremental signal delays for filter algorithms
D	Provide access for debugging software

37. - E7G09

What will be the output voltage of the circuit shown in Figure E7-3 if R1 is 1000 ohms, RF is 10,000 ohms, and 0.23 volts DC is applied to the input?

Select	Answer
A	-0.23 volts
B	2.3 volts
C	-2.3 volts
D	0.23 volts

38. - E7H10

What information is contained in the lookup table of a direct digital synthesizer (DDS)?

Select	Answer
A	Amplitude values that represent the desired waveform
B	The phase relationship between a voltage-controlled oscillator and the output waveform
C	The phase relationship between a reference oscillator and the output waveform
D	Frequently used receiver and transmitter frequencies

39. - E8A10

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

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

40. - E8B05

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus-or-minus 5 kHz when the maximum modulation frequency is 3 kHz?

Select	Answer
A	0.167
B	0.6
C	1.67
D	60

41. - E8C01

How is Forward Error Correction implemented?

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

42. - E8D05

What is the most common method of reducing key clicks?

Select	Answer
A	Reduce keying waveform rise and fall times
B	Low-pass filters at the transmitter output
C	High-pass filters at the transmitter output
D	Increase keying waveform rise and fall times

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	126 watts
B	2000 watts
C	317 watts
D	300 watts

44. - E9B03

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

Select	Answer
A	12 dB
B	18 dB
C	24 dB
D	14 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 lobes align more in the direction of the wire
B	The vertical angle increases
C	The lobes become more perpendicular to the wire
D	The front-to-back ratio decreases

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

47. - E9E11

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

Select	Answer
A	It creates a low-angle radiation pattern
B	It allows single-band antennas to operate on other bands
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. - E9F01

What is the velocity factor of a transmission line?

Select	Answer
A	The ratio of the characteristic impedance of the line to the terminating impedance
B	The velocity of the wave in the transmission line multiplied by the velocity of light in a vacuum
C	The index of shielding for coaxial cable
D	The velocity of the wave in the transmission line divided by the velocity of light in a vacuum

49. - E9G06

On the Smith chart shown in Figure E9-3, what is the name for the large outer circle on which the reactance arcs terminate?

Select	Answer
A	Impedance axis
B	Polar axis
C	Prime axis
D	Reactance axis

50. - E9H03

What is Receiving Directivity Factor (RDF)?

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

Figure E5-1

Figure E7-2

Figure E7-3

Figure E9-1

Figure E9-3