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

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1. - E0A08

What does SAR measure?

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

2. - E1A03

What is the maximum legal carrier frequency on the 20 meter band for transmitting USB AFSK digital signals having a 1 kHz bandwidth?

Select	Answer
A	14.349 MHz
B	14.100 MHz
C	14.070 MHz
D	14.149 MHz

3. - E1B09

Which amateur stations may be operated under RACES rules?

Select	Answer
A	Any FCC-licensed amateur station except a Technician Class
B	Only those club stations licensed to Amateur Extra Class operators
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. - 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	ITU reciprocal license
C	IARP agreement
D	All these choices are correct

5. - E1D01

What is the definition of telemetry?

Select	Answer
A	One-way transmission that initiates, modifies, or terminates the functions of a device at a distance
B	Two-way transmissions of data
C	One-way transmission of measurements at a distance from the measuring instrument
D	Two-way transmissions in excess of 1000 feet

6. - E1E05

What is the minimum passing score on all amateur operator license examinations?

Select	Answer
A	Minimum passing score of 74%
B	Minimum passing score of 70%
C	Minimum passing score of 77%
D	Minimum passing score of 80%

7. - E1F02

What privileges are authorized in the U.S. to persons holding an amateur service license granted by the government of Canada?

Select	Answer
A	The operating terms and conditions of the Canadian amateur service license, not to exceed U.S. Amateur Extra Class license privileges
B	None, they must obtain a U.S. license
C	Full privileges, up to and including those of the Amateur Extra Class license, on the 80, 40, 20, 15, and 10 meter bands
D	All privileges of the Amateur Extra Class license

8. - E2A12

What is the purpose of digital store-and-forward functions on an amateur radio satellite?

Select	Answer
A	To upload operational software for the transponder
B	To store digital messages in the satellite for later download by other stations
C	To relay messages between satellites
D	To delay download of telemetry between satellites

9. - E2B06

What is vestigial sideband modulation?

Select	Answer
A	Amplitude modulation in which one complete sideband and a portion of the other are transmitted
B	Spread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation
C	Narrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier
D	A type of modulation in which one sideband is inverted

10. - E2C10

Why might a DX station state that they are listening on another frequency?

Select	Answer
A	Because the DX station may be transmitting on a frequency that is prohibited to some responding stations
B	All these choices are correct
C	To improve operating efficiency by reducing interference
D	To separate the calling stations from the DX station

11. - E2D11

Which of the following data are used by the APRS network to communicate station location?

Select	Answer
A	Radio direction finding spectrum analysis
B	Polar coordinates
C	Latitude and longitude
D	Time and frequency

12. - E2E06

What is the most common data rate used for HF packet?

Select	Answer
A	110 baud
B	48 baud
C	300 baud
D	1200 baud

13. - E3A07

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

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

14. - E3B11

At what time of day can sporadic E propagation occur?

Select	Answer
A	Only in hours of darkness
B	Only around sunset
C	Only around sunset and sunrise
D	Any time

15. - E3C12

How does the maximum range of ground-wave propagation change when the signal frequency is increased?

Select	Answer
A	It increases
B	It peaks at roughly 14 MHz
C	It decreases
D	It stays the same

16. - E4A05

What is the purpose of the prescaler function on a frequency counter?

Select	Answer
A	It divides a higher frequency signal so a low-frequency counter can display the input frequency
B	It amplifies low-level signals for more accurate counting
C	It prevents oscillation in a low-frequency counter circuit
D	It multiplies a higher frequency signal so a low-frequency counter can display the operating frequency

17. - E4B09

What is indicated if the current reading on an RF ammeter placed in series with the antenna feed line of a transmitter increases as the transmitter is tuned to resonance?

Select	Answer
A	There is more power going into the antenna
B	The transmitter is not properly neutralized
C	There is an impedance mismatch between the antenna and feed line
D	There is possibly a short to ground in the feed line

18. - E4C03

What is the term for the suppression in an FM receiver of one signal by another stronger signal on the same frequency?

Select	Answer
A	Desensitization
B	Cross-modulation interference
C	Capture effect
D	Frequency discrimination

19. - E4D08

What causes intermodulation in an electronic circuit?

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

20. - E4E06

What is one type of electrical interference that might be caused by a nearby personal computer?

Select	Answer
A	A whining type noise that continually pulses off and on
B	A clicking noise at intervals of a few seconds
C	The appearance of unstable modulated or unmodulated signals at specific frequencies
D	A loud AC hum in the audio output of your station receiver

21. - E5A06

What is the magnitude of the circulating current within the components of a parallel LC circuit at resonance?

Select	Answer
A	It equals 2 multiplied by pi, multiplied by frequency, multiplied by inductance
B	It equals 1 divided by the quantity 2 times pi, multiplied by the square root of inductance L multiplied by capacitance C
C	It is at a minimum
D	It is at a maximum

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

23. - E5C01

Which of the following represents capacitive reactance in rectangular notation?

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

24. - E5D08

How many watts are consumed in a circuit having a power factor of 0.6 if the input is 200VAC at 5 amperes?

Select	Answer
A	200 watts
B	1600 watts
C	1000 watts
D	600 watts

25. - E6A02

Which of the following semiconductor materials contains excess free electrons?

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

26. - E6B10

In Figure E6-2, what is the schematic symbol for a light-emitting diode?

Select	Answer
A	1
B	6
C	7
D	5

27. - E6C11

In Figure E6-3, what is the schematic symbol for the NOT operation (inverter)?

Select	Answer
A	4
B	5
C	6
D	2

28. - E6D05

What is one reason for using ferrite cores rather than powdered iron in an inductor?

Select	Answer
A	Ferrite toroids are easier to use with surface mount technology
B	Ferrite toroids generally have better temperature stability
C	Ferrite toroids generally require fewer turns to produce a given inductance value
D	Ferrite toroids generally have lower initial permeability

29. - E6E01

Why is gallium arsenide (GaAs) useful for semiconductor devices operating at UHF and higher frequencies?

Select	Answer
A	Higher noise figures
B	Higher electron mobility
C	Lower transconductance
D	Lower junction voltage drop

30. - E6F04

What is the photovoltaic effect?

Select	Answer
A	The tendency of a battery to discharge when exposed to light
B	The conversion of voltage to current when exposed to light
C	The conversion of electrical energy to mechanical energy
D	The conversion of light to electrical energy

31. - E7A02

What is the function of a decade counter?

Select	Answer
A	It decodes a decimal number for display on a seven-segment LED display
B	It decodes a binary number for display on a seven-segment LED display
C	It produces 10 output pulses for every input pulse
D	It produces one output pulse for every 10 input pulses

32. - E7B15

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

Select	Answer
A	Use a resistor in series with the emitter
B	All these choices are correct
C	Select transistors with high beta
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 gain of the RF stage preceding the filter
B	The DC voltage applied to the quartz crystal
C	The amplitude of the signals passing through the filter
D	The relative frequencies of the individual crystals

34. - E7D01

How does a linear electronic voltage regulator work?

Select	Answer
A	It has a ramp voltage as its output
B	The control element duty cycle is proportional to the line or load conditions
C	It eliminates the need for a pass transistor
D	The conduction of a control element is varied to maintain a constant output voltage

35. - E7E04

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

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

36. - E7F07

What function is performed by a Fast Fourier Transform?

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

37. - E7G10

What absolute voltage gain can be expected from the circuit in Figure E7-3 when R1 is 1800 ohms and RF is 68 kilohms?

Select	Answer
A	1
B	38
C	76
D	0.03

38. - E7H02

What is a microphonic?

Select	Answer
A	Distortion caused by RF pickup on the microphone cable
B	Changes in oscillator frequency due to mechanical vibration
C	An IC used for amplifying microphone signals
D	Excess loading of the microphone by an oscillator

39. - E8A08

Why would a direct or flash conversion analog-to-digital converter be useful for a software defined radio?

Select	Answer
A	Very low power consumption decreases frequency drift
B	Very high speed allows digitizing high frequencies
C	Immunity to out-of-sequence coding reduces spurious responses
D	All these choices are correct

40. - E8B06

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz when the maximum modulation frequency is 3.5 kHz?

Select	Answer
A	0.47
B	2.14
C	0.214
D	47

41. - E8C09

Which digital code allows only one bit to change between sequential code values?

Select	Answer
A	Gray code
B	Excess 3 code
C	Extended Binary Coded Decimal Interchange Code
D	Binary Coded Decimal Code

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

43. - E9A10

Which of the following improves the efficiency of a ground-mounted quarter-wave vertical antenna?

Select	Answer
A	All these choices are correct
B	Installing a radial system
C	Shortening the radiating element
D	Isolating the coax shield from ground

44. - E9B05

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

Select	Answer
A	Elevation
B	Azimuth
C	Radiation resistance
D	Polarization

45. - E9C02

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/4 wavelength apart and fed 90 degrees out of phase?

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

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

47. - E9E09

Which of the following is used to shunt-feed a grounded tower at its base?

Select	Answer
A	Double-bazooka match
B	Hairpin match
C	Gamma match
D	All these choices are correct

48. - E9F06

What is the approximate physical length of an air-insulated, parallel conductor transmission line that is electrically 1/2 wavelength long at 14.10 MHz?

Select	Answer
A	7.0 meters
B	8.5 meters
C	13.3 meters
D	10.6 meters

49. - E9G07

On the Smith chart shown in Figure E9-3, what is the only straight line shown?

Select	Answer
A	The reactance axis
B	The resistance axis
C	The current axis
D	The voltage axis

50. - E9H05

What is the main drawback of a small wire-loop antenna for direction finding?

Select	Answer
A	It is practical for use only on VHF and higher bands
B	It has a bidirectional pattern
C	It has no clearly defined null
D	All these choices are correct

Figure E6-2

Figure E6-3

Figure E7-3

Figure E9-2

Figure E9-3