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	Signal Amplification Rating
D	The rate of RF energy reflected from stationary terrain

2. - E1A11

Which of the following describes authorization or licensing required when operating an amateur station aboard a U.S.-registered vessel in international waters?

Select	Answer
A	Any amateur license with an FCC Marine or Aircraft endorsement
B	Any FCC-issued amateur license
C	Only General Class or higher amateur licenses
D	An unrestricted Radiotelephone Operator Permit

3. - E1B09

Which amateur stations may be operated under RACES rules?

Select	Answer
A	Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served
B	Only those club stations licensed to Amateur Extra Class operators
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. - 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 there is no control operator
B	Under local control a control operator is not required to be present at a control point
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 and 33 cm
B	33 cm and 13 cm
C	70 cm only
D	70 cm and 13 cm

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 ARRL
C	The FCC
D	The VEs

7. - E1F09

Which of the following conditions apply when transmitting spread spectrum emissions?

Select	Answer
A	A station transmitting SS emission must not cause harmful interference to other stations employing other authorized emissions
B	The transmission must not be used to obscure the meaning of any communication
C	The transmitting station must be in an area regulated by the FCC or in a country that permits SS emissions
D	All these choices are correct

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	Upper sideband on the uplink becomes lower sideband on the downlink, and vice versa
C	Signal position in the band is reversed
D	All these choices are correct

9. - E2B07

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

Select	Answer
A	Luminance
B	Chroma
C	Hue
D	Spectral intensity

10. - E2C09

What type of equipment is commonly used to implement an amateur radio mesh network?

Select	Answer
A	A 2 meter VHF transceiver with a 1200 baud modem
B	A wireless router running custom firmware
C	A 440 MHz transceiver with a 9600 baud modem
D	An optical cable connection between the USB ports of 2 separate computers

11. - E2D09

What type of modulation is used for JT65 contacts?

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

12. - E2E02

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

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

13. - E3A04

What do Hepburn maps predict?

Select	Answer
A	Locations of auroral reflecting zones
B	Likelihood of rain scatter along cold or warm fronts
C	Probability of tropospheric propagation
D	Sporadic E propagation

14. - E3B07

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

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

15. - E3C10

What does the 304A solar parameter measure?

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

16. - E4A11

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

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

17. - E4B01

Which of the following factors most affects the accuracy of a frequency counter?

Select	Answer
A	Input attenuator accuracy
B	Temperature coefficient of the logic
C	Decade divider accuracy
D	Time base accuracy

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	14.445 MHz
B	14.755 MHz
C	15.210 MHz
D	13.845 MHz

19. - E4D08

What causes intermodulation in an electronic circuit?

Select	Answer
A	Too little gain
B	Lack of neutralization
C	Nonlinear circuits or devices
D	Positive feedback

20. - E4E10

What might be the cause of a loud roaring or buzzing AC line interference that comes and goes at intervals?

Select	Answer
A	A malfunctioning illuminated advertising display
B	A defective doorbell or doorbell transformer inside a nearby residence
C	All these choices are correct
D	Arcing contacts in a thermostatically controlled device

21. - E5A05

What is the result of increasing the Q of an impedance-matching circuit?

Select	Answer
A	Matching range is increased
B	It has no effect on impedance matching
C	Matching bandwidth is increased
D	Matching bandwidth is decreased

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. - E5C01

Which of the following represents capacitive reactance in rectangular notation?

Select	Answer
A	Omega
B	+jX
C	Delta
D	-jX

24. - E5D04

Why are short connections used at microwave frequencies?

Select	Answer
A	To reduce noise figure
B	To increase compensating capacitance
C	To reduce phase shift along the connection
D	To increase neutralizing resistance

25. - E6A10

In Figure E6-1, what is the schematic symbol for an N-channel dual-gate MOSFET?

Select	Answer
A	6
B	2
C	4
D	5

26. - E6B01

What is the most useful characteristic of a Zener diode?

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

27. - E6C10

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

Select	Answer
A	3
B	2
C	1
D	4

28. - E6D07

What is current in the primary winding of a transformer called if no load is attached to the secondary?

Select	Answer
A	Magnetizing current
B	Stabilizing current
C	Excitation current
D	Direct current

29. - E6E08

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

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

30. - E6F03

What is the most common configuration of an optoisolator or optocoupler?

Select	Answer
A	A frequency modulated helium-neon laser
B	A lens and a photomultiplier
C	An amplitude modulated helium-neon laser
D	An LED and a phototransistor

31. - E7A11

What type of logic defines "1" as a high voltage?

Select	Answer
A	Positive Logic
B	Assertive Logic
C	Reverse Logic
D	Negative logic

32. - E7B12

What type of amplifier circuit is shown in Figure E7-1?

Select	Answer
A	Common base
B	Common emitter
C	Emitter follower
D	Common collector

33. - E7C05

Which filter type is described as having ripple in the passband and a sharp cutoff?

Select	Answer
A	An active LC filter
B	A Butterworth filter
C	A passive op-amp filter
D	A Chebyshev filter

34. - E7D13

What is the equation for calculating power dissipated by a series linear voltage regulator?

Select	Answer
A	Output voltage multiplied by output current
B	Input voltage divided by output current
C	Voltage difference from input to output multiplied by output current
D	Input voltage multiplied by input current

35. - E7E02

What is the function of a reactance modulator?

Select	Answer
A	To produce PM or FM signals by using an electrically variable inductance or capacitance
B	To produce PM signals by using an electrically variable resistance
C	To produce AM signals by using an electrically variable resistance
D	To produce AM signals by using an electrically variable inductance or capacitance

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 from the time domain to the frequency domain
C	Converting digital signals to analog form
D	Converting analog signals to digital form

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 logarithmically with increasing frequency
D	It decreases linearly with increasing frequency

38. - E7H08

Which of the following components can be used to reduce thermal drift in crystal oscillators?

Select	Answer
A	Non-inductive resistors
B	Toroidal inductors
C	NP0 capacitors
D	Wirewound resistors

39. - E8A10

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

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

40. - E8B01

What is the modulation index of an FM signal?

Select	Answer
A	The ratio of modulating signal amplitude to frequency deviation
B	The ratio of frequency deviation to modulating signal frequency
C	The bandwidth of the transmitted signal divided by the modulating signal frequency
D	The type of modulation used by the transmitter

41. - E8C10

How may data rate be increased without increasing bandwidth?

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

42. - E8D11

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

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

43. - E9A01

What is an isotropic antenna?

Select	Answer
A	A grounded antenna used to measure Earth conductivity
B	A spacecraft antenna used to direct signals toward Earth
C	A theoretical, omnidirectional antenna used as a reference for antenna gain
D	A horizontally polarized antenna used to compare Yagi antennas

44. - E9B05

What type of antenna pattern is shown in Figure E9-2?

Select	Answer
A	Azimuth
B	Polarization
C	Radiation resistance
D	Elevation

45. - E9C11

How is the far-field elevation pattern of a vertically polarized antenna affected by being mounted over seawater versus soil?

Select	Answer
A	Additional higher vertical angle lobes will appear
B	Fewer vertical angle lobes will be present
C	The low-angle radiation increases
D	The low-angle radiation decreases

46. - E9D12

Which of the following would provide the best RF ground for your station?

Select	Answer
A	An electrically short connection to a metal water pipe
B	An electrically short connection to 3 or 4 interconnected ground rods via a series RF choke
C	An electrically short connection to 3 or 4 interconnected ground rods driven into the Earth
D	A 50-ohm resistor connected to ground

47. - E9E07

What parameter describes the interactions at the load end of a mismatched transmission line?

Select	Answer
A	Reflection coefficient
B	Characteristic impedance
C	Velocity factor
D	Dielectric constant

48. - E9F04

What impedance does a 1/2-wavelength transmission line present to a generator when the line is shorted at the far end?

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

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 antenna electrical wavelength
C	In fractions of transmission line electrical frequency
D	In fractions of antenna electrical frequency

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 allows DF antennas to receive signals at different vertical angles
C	It increases the sensitivity of a DF antenna array
D	It provides diversity reception that cancels multipath signals

Figure E6-1

Figure E6-3

Figure E7-1

Figure E9-2