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

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1. - E0A10

What toxic material may be present in some electronic components such as high voltage capacitors and transformers?

Select	Answer
A	Polymorphic silicon
B	Polyethylene
C	Polychlorinated biphenyls
D	Polytetrafluoroethylene

2. - E1A01

Which of the following carrier frequencies is illegal for LSB AFSK emissions on the 17 meter band RTTY and data segment of 18.068 to 18.110 MHz?

Select	Answer
A	18.100 MHz
B	18.107 MHz
C	18.110 MHz
D	18.068 MHz

3. - E1B10

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

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

4. - E1C11

Which of the following operating arrangements allows an FCC-licensed U.S. citizen to operate in many European countries, and alien amateurs from many European countries to operate in the U.S.?

Select	Answer
A	CEPT agreement
B	IARP agreement
C	All these choices are correct
D	ITU reciprocal license

5. - E1D08

Which VHF amateur bands have frequencies authorized for space stations?

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

6. - E1E12

What must the VE team do with the application form if the examinee does not pass the exam?

Select	Answer
A	Send the application form to the FCC and inform the FCC of the grade
B	Destroy the application form
C	Return the application document to the examinee
D	Maintain the application form with the VEC's records

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

8. - E2A02

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

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

9. - E2B07

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

Select	Answer
A	Spectral intensity
B	Chroma
C	Luminance
D	Hue

10. - E2C08

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

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

11. - E2D01

Which of the following digital modes is designed for meteor scatter communications?

Select	Answer
A	APRS
B	Hellschreiber
C	WSPR
D	MSK144

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 applies the data signal to the transmitter VFO, while AFSK transmits tones via phone
C	Direct FSK occupies less bandwidth
D	Direct FSK can transmit faster baud rates

13. - E3A07

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

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

14. - E3B02

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

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

15. - E3C07

Which of the following descriptors indicates the greatest solar flare intensity?

Select	Answer
A	Class X
B	Class B
C	Class A
D	Class M

16. - E4A01

Which of the following limits the highest frequency signal that can be accurately displayed on a digital oscilloscope?

Select	Answer
A	Q of the circuit
B	All these choices are correct
C	Sampling rate of the analog-to-digital converter
D	Amount of memory

17. - E4B06

How much power is being absorbed by the load when a directional power meter connected between a transmitter and a terminating load reads 100 watts forward power and 25 watts reflected power?

Select	Answer
A	25 watts
B	100 watts
C	125 watts
D	75 watts

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	-155 dBm
C	-174 dBm
D	-164 dBm

19. - E4D06

What is the term for spurious signals generated by the combination of two or more signals in a non-linear device or circuit?

Select	Answer
A	Intermodulation
B	Neutralization
C	Amplifier desensitization
D	Adjacent channel interference

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. - E5A12

What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 3.7 MHz and a Q of 118?

Select	Answer
A	436.6 kHz
B	31.4 kHz
C	15.7 kHz
D	218.3 kHz

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

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 6
C	Point 4
D	Point 5

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

25. - E6A12

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

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

26. - E6B01

What is the most useful characteristic of a Zener diode?

Select	Answer
A	A negative resistance region
B	A constant current drop under conditions of varying voltage
C	An internal capacitance that varies with the applied voltage
D	A constant voltage drop under conditions of varying current

27. - E6C09

What is a Programmable Logic Device (PLD)?

Select	Answer
A	A type of transistor whose gain can be changed by digital logic circuits
B	Programmable equipment used for testing digital logic integrated circuits
C	A logic circuit that can be modified during use
D	A programmable collection of logic gates and circuits in a single integrated circuit

28. - E6D10

What is a primary advantage of using a toroidal core instead of a solenoidal core in an inductor?

Select	Answer
A	Toroidal cores exhibit greater hysteresis
B	Toroidal cores make it easier to couple the magnetic energy into other components
C	Toroidal cores have lower Q characteristics
D	Toroidal cores confine most of the magnetic field within the core material

29. - E6E12

Why are DIP through-hole package ICs not typically used at UHF and higher frequencies?

Select	Answer
A	Unsuitable for combining analog and digital signals
B	Excessive lead length
C	Too many pins
D	Epoxy coating is conductive above 300 MHz

30. - E6F08

Why are optoisolators often used in conjunction with solid-state circuits when switching 120 VAC?

Select	Answer
A	Optoisolators provide a low impedance link between a control circuit and a power circuit
B	Optoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched
C	Optoisolators provide impedance matching between the control circuit and power circuit
D	Optoisolators eliminate the effects of reflected light in the control circuit

31. - E7A01

Which circuit is bistable?

Select	Answer
A	An OR gate
B	An AND gate
C	A flip-flop
D	A bipolar amplifier

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. - E7C04

How does an impedance-matching circuit transform a complex impedance to a resistive impedance?

Select	Answer
A	It introduces transconductance to cancel the reactive part of impedance
B	It cancels the reactive part of the impedance and changes the resistive part to a desired value
C	It introduces negative resistance to cancel the resistive part of impedance
D	Reactive currents are dissipated in matched resistances

34. - E7D12

What is the dropout voltage of an analog voltage regulator?

Select	Answer
A	Maximum output voltage drops when the input voltage is varied over its specified range
B	Minimum input voltage for rated power dissipation
C	Minimum input-to-output voltage required to maintain regulation
D	Maximum that the output voltage may decrease at rated load

35. - E7E04

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

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

36. - E7F07

What function is performed by a Fast Fourier Transform?

Select	Answer
A	Converting 8-bit data to 16-bit data
B	Converting digital signals to analog form
C	Converting analog signals to digital form
D	Converting digital signals from the time domain to the frequency domain

37. - E7G01

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

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

38. - E7H10

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

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

39. - E8A03

What type of wave does a Fourier analysis show to be made up of sine waves of a given fundamental frequency plus all its harmonics?

Select	Answer
A	A sawtooth wave
B	A cosine wave
C	A square wave
D	A sine wave

40. - E8B02

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

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

41. - E8C08

How does ARQ accomplish error correction?

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

42. - E8D02

What spread spectrum communications technique uses a high-speed binary bit stream to shift the phase of an RF carrier?

Select	Answer
A	Direct sequence
B	Frequency hopping
C	Binary phase-shift keying
D	Phase compandored spread spectrum

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	252 watts
D	63.2 watts

44. - E9B01

In the antenna radiation pattern shown in Figure E9-1, what is the beamwidth?

Select	Answer
A	75 degrees
B	30 degrees
C	25 degrees
D	50 degrees

45. - E9C09

Which of the following describes a G5RV antenna?

Select	Answer
A	A multi-band dipole antenna fed with coax and a balun through a selected length of open wire transmission line
B	A phased array antenna consisting of multiple loops
C	A wide band dipole using shorted coaxial cable for the radiating elements and fed with a�4:1 balun
D	A multi-band trap antenna

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

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 index of shielding for coaxial cable
C	The velocity of the wave in the transmission line divided by the velocity of light in a vacuum
D	The velocity of the wave in the transmission line multiplied by the velocity of light in a vacuum

49. - E9G01

Which of the following can be calculated using a Smith chart?

Select	Answer
A	Radiation resistance
B	Antenna radiation pattern
C	Radio propagation
D	Impedance along transmission lines

50. - E9H08

What is the function of a sense antenna?

Select	Answer
A	It modifies the pattern of a DF antenna array to provide a null in one direction
B	It increases the sensitivity of a DF antenna array
C	It allows DF antennas to receive signals at different vertical angles
D	It provides diversity reception that cancels multipath signals

Figure E5-1

Figure E9-1