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	The rate at which RF energy is absorbed by the body
C	The rate of RF energy reflected from stationary terrain
D	Signal Amplification Rating

2. - E1A07

What is the maximum power permitted on the 2200 meter band?

Select	Answer
A	100 watts PEP
B	1 watt EIRP (Equivalent isotropic radiated power)
C	5 watts EIRP (Equivalent isotropic radiated power)
D	50 watts PEP

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 except a Technician Class
C	Any FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)
D	Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served

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	1.0
D	3.0

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 space station licensee
D	Any amateur station so designated by the ITU

6. - E1E03

What is a Volunteer Examiner Coordinator?

Select	Answer
A	An organization that has entered into an agreement with the FCC to coordinate, prepare, and administer amateur operator license examinations
B	A person who has volunteered to administer amateur operator license examinations
C	The person who has entered into an agreement with the FCC to be the VE session manager
D	A person who has volunteered to prepare amateur operator license examinations

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

8. - E2A10

What type of satellite appears to stay in one position in the sky?

Select	Answer
A	HEO
B	Geostationary
C	Geomagnetic
D	LEO

9. - E2B04

How is color information sent in analog SSTV?

Select	Answer
A	Color is sent in a color burst at the end of each line
B	Color is amplitude modulated on the frequency modulated intensity signal
C	Color lines are sent sequentially
D	Color information is sent on a 2.8 kHz subcarrier

10. - E2C03

From which of the following bands is amateur radio contesting generally excluded?

Select	Answer
A	2 meters
B	33 centimeters
C	6 meters
D	30 meters

11. - E2D04

What technology is used to track, in real time, balloons carrying amateur radio transmitters?

Select	Answer
A	Bandwidth compressed LORAN
B	APRS
C	Ultrasonics
D	Doppler shift of beacon signals

12. - E2E04

What is indicated when one of the ellipses in an FSK crossed-ellipse display suddenly disappears?

Select	Answer
A	One of the signal filters is saturated
B	Selective fading has occurred
C	The receiver has drifted 5 kHz from the desired receive frequency
D	The mark and space signal have been inverted

13. - E3A14

What is meant by circularly polarized electromagnetic waves?

Select	Answer
A	Waves produced by a loop antenna
B	Waves with an electric field bent into a circular shape
C	Waves that circle the Earth
D	Waves with a rotating electric field

14. - E3B03

What is the best time of day for transequatorial propagation?

Select	Answer
A	Afternoon or early evening
B	Late at night
C	Morning
D	Noon

15. - E3C15

What might be indicated by a sudden rise in radio background noise across a large portion of the HF spectrum?

Select	Answer
A	Increased transequatorial propagation is likely
B	A temperature inversion has occurred
C	Long-path propagation is likely
D	A solar flare has occurred

16. - E4A09

Which of the following is good practice when using an oscilloscope probe?

Select	Answer
A	All these choices are correct
B	Keep the signal ground connection of the probe as short as possible
C	Never use a high-impedance probe to measure a low-impedance circuit
D	Never use a DC-coupled probe to measure an AC circuit

17. - E4B11

Which of the following can be measured with a vector network analyzer?

Select	Answer
A	Reflection coefficient
B	Input impedance
C	Output impedance
D	All these choices are correct

18. - E4C07

What does the MDS of a receiver represent?

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

19. - E4D01

What is meant by the blocking dynamic range of a receiver?

Select	Answer
A	The difference in dB between the noise floor and the level of an incoming signal that will cause 1 dB of gain compression
B	The minimum difference in dB between two signals which produce third-order intermodulation products greater than the noise floor
C	The minimum difference in dB between the levels of two FM signals that will cause one signal to block the other
D	The difference in dB between the noise floor and the third-order intercept point

20. - E4E03

Which of the following signals might a receiver noise blanker be able to remove from desired signals?

Select	Answer
A	Signals that are constant at all IF levels
B	Signals that have a sharply peaked frequency distribution
C	Signals that appear across a wide bandwidth
D	Signals that appear at one IF but not another

21. - E5A13

What is an effect of increasing Q in a series resonant circuit?

Select	Answer
A	Internal voltages increase
B	Parasitic effects are minimized
C	Phase shift can become uncontrolled
D	Fewer components are needed for the same performance

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 leading the current
B	68.2 degrees with the voltage lagging the current
C	68.2 degrees with the voltage leading the current
D	14.0 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 4
B	Point 5
C	Point 2
D	Point 6

24. - E5D14

What is reactive power?

Select	Answer
A	Power consumed in circuit Q
B	Power lost because of capacitor leakage
C	Wattless, nonproductive power
D	Power consumed in wire resistance in an inductor

25. - E6A12

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

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

26. - E6B04

What type of semiconductor device is designed for use as a voltage-controlled capacitor?

Select	Answer
A	Tunnel diode
B	Zener diode
C	Silicon-controlled rectifier
D	Varactor diode

27. - E6C03

What is tri-state logic?

Select	Answer
A	Proprietary logic devices manufactured by Tri-State Devices
B	Low-power logic devices designed to operate at 3 volts
C	Logic devices that utilize ternary math
D	Logic devices with 0, 1, and high-impedance output states

28. - E6D02

What is the equivalent circuit of a quartz crystal?

Select	Answer
A	Motional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in parallel
B	Motional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in series
C	Motional inductance and loss resistance in series, paralleled with motional capacitance and a capacitor representing electrode and stray capacitance
D	Motional capacitance, motional inductance, and loss resistance in series, all in parallel with a shunt capacitor representing electrode and stray capacitance

29. - E6E07

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

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

30. - E6F01

What absorbs the energy from light falling on a photovoltaic cell?

Select	Answer
A	Protons
B	Holes
C	Photons
D	Electrons

31. - E7A03

Which of the following can divide the frequency of a pulse train by 2?

Select	Answer
A	A flip-flop
B	An OR gate
C	A multiplexer
D	An XOR gate

32. - E7B11

In Figure E7-1, what is the purpose of R3?

Select	Answer
A	Emitter bypass
B	Self bias
C	Output load resistor
D	Fixed bias

33. - E7C10

Which of the following filters would be the best choice for use in a 2 meter band repeater duplexer?

Select	Answer
A	An L-C filter
B	A crystal filter
C	A DSP filter
D	A cavity filter

34. - E7D05

Which of the following types of linear voltage regulator places a constant load on the unregulated voltage source?

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

35. - E7E05

What circuit is added to an FM transmitter to boost the higher audio frequencies?

Select	Answer
A	A heterodyne suppressor
B	A de-emphasis network
C	A pre-emphasis network
D	A heterodyne enhancer

36. - E7F05

How frequently must an analog signal be sampled by an analog-to-digital converter so that the signal can be accurately reproduced?

Select	Answer
A	At least twice the rate of the highest frequency component of the signal
B	At least half the rate of the highest frequency component of the signal
C	At the same rate as the highest frequency component of the signal
D	At four times the rate of the highest frequency component of the signal

37. - E7G08

How does the gain of an ideal operational amplifier vary with frequency?

Select	Answer
A	It does not vary with frequency
B	It increases linearly with increasing frequency
C	It decreases linearly with increasing frequency
D	It decreases logarithmically with increasing frequency

38. - E7H10

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

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

39. - E8A02

Which of the following is a type of analog-to-digital conversion?

Select	Answer
A	Level shifting
B	Harmonic regeneration
C	Successive approximation
D	Phase reversal

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	2000
B	3
C	1/3
D	6000

41. - E8C05

What is the approximate bandwidth of a 13-WPM International Morse Code transmission?

Select	Answer
A	104 Hz
B	13 Hz
C	26 Hz
D	52 Hz

42. - E8D11

What is one advantage of using ASCII code for data communications?

Select	Answer
A	It is possible to transmit both upper and lower case text
B	It includes built-in error correction features
C	It contains fewer information bits per character than any other code
D	It uses one character as a shift code to send numeric and special characters

43. - E9A08

What is antenna bandwidth?

Select	Answer
A	The angle formed between two imaginary lines drawn through the element ends
B	The frequency range over which an antenna satisfies a performance requirement
C	Antenna length divided by the number of elements
D	The angle between the half-power radiation points

44. - E9B01

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

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

45. - E9C01

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed 180 degrees out of phase?

Select	Answer
A	Cardioid
B	A figure-8 broadside to the axis of the array
C	A figure-8 oriented along the axis of the array
D	Omni-directional

46. - E9D04

Why should an HF mobile antenna loading coil have a high ratio of reactance to resistance?

Select	Answer
A	To minimize the Q
B	To minimize losses
C	To lower the radiation angle
D	To swamp out harmonics

47. - E9E05

How must an antenna's driven element be tuned to use a hairpin matching system?

Select	Answer
A	The driven element reactance must be capacitive
B	The driven element radiation resistance must be higher than the characteristic impedance of the transmission line
C	The driven element reactance must be inductive
D	The driven element resonance must be lower than the operating frequency

48. - E9F01

What is the velocity factor of a transmission line?

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

49. - E9G11

How are the wavelength scales on a Smith chart calibrated?

Select	Answer
A	In fractions of transmission line electrical wavelength
B	In fractions of transmission line electrical frequency
C	In fractions of antenna electrical frequency
D	In fractions of antenna electrical wavelength

50. - E9H11

What feature of a cardioid pattern antenna makes it useful for direction finding?

Select	Answer
A	Broadband response
B	High radiation angle
C	A very sharp peak
D	A very sharp single null

Figure E5-1

Figure E7-1

Figure E9-1