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

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1. - E0A06

Why are there separate electric (E) and magnetic (H) field MPE limits?

Select	Answer
A	Ground reflections and scattering make the field strength vary with location
B	All these choices are correct
C	The body reacts to electromagnetic radiation from both the E and H fields
D	E field and H field radiation intensity peaks can occur at different locations

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	18.068 MHz
C	18.110 MHz
D	18.107 MHz

3. - E1B07

To what type of regulations does PRB-1 apply?

Select	Answer
A	FAA tower height limits
B	State and local zoning
C	Homeowners associations
D	Use of wireless devices in vehicles

4. - E1C14

How long must an operator wait after filing a notification with the Utilities Technology Council (UTC) before operating on the 2200 meter or 630 meter band?

Select	Answer
A	Operations may commence immediately, and may continue unless interference is reported by the UTC
B	Operators may not operate until a test signal has been transmitted in coordination with the local power company
C	Operators must not operate until approval is received
D	Operators may operate after 30 days, providing they have not been told that their station is within 1 km of PLC systems using those frequencies

5. - E1D09

Which UHF amateur bands have frequencies authorized for space stations?

Select	Answer
A	70 cm only
B	33 cm and 13 cm
C	70 cm and 13 cm
D	70 cm and 33 cm

6. - E1E04

Which of the following best describes the Volunteer Examiner accreditation process?

Select	Answer
A	The prospective VE obtains accreditation from the FCC
B	The procedure by which a VEC confirms that the VE applicant meets FCC requirements to serve as an examiner
C	Each General, Advanced and Amateur Extra Class operator is automatically accredited as a VE when the license is granted
D	The amateur operator applying must pass a VE examination administered by the FCC Enforcement Bureau

7. - E1F01

On what frequencies are spread spectrum transmissions permitted?

Select	Answer
A	Only on amateur frequencies above 222 MHz
B	Only on amateur frequencies above 50 MHz
C	Only on amateur frequencies above 144 MHz
D	Only on amateur frequencies above 420 MHz

8. - E2A06

What are Keplerian elements?

Select	Answer
A	High-emission heater filaments used in magnetron tubes
B	Parameters that define the orbit of a satellite
C	Phase reversing elements in a Yagi antenna
D	Encrypting codes used for spread spectrum modulation

9. - E2B11

What is the function of the Vertical Interval Signaling (VIS) code sent as part of an SSTV transmission?

Select	Answer
A	To provide vertical synchronization
B	To lock the color burst oscillator in color SSTV images
C	To identify the call sign of the station transmitting
D	To identify the SSTV mode being used

10. - E2C02

Which of the following best describes the term self-spotting? in connection with HF contest operating?

Select	Answer
A	The often-prohibited practice of posting one's own call sign and frequency on a spotting network
B	A manual technique for rapidly zero beating or tuning to a station's frequency before calling that station
C	An automatic method for rapidly zero beating or tuning to a station's frequency before calling that station
D	The acceptable practice of manually posting the call signs of stations on a spotting network

11. - E2D03

Which of the following digital modes is especially useful for EME communications?

Select	Answer
A	Olivia
B	MSK144
C	PACTOR III
D	JT65

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

13. - E3A09

Which of the following frequency ranges is most suited for meteor scatter communications?

Select	Answer
A	28 MHz - 148 MHz
B	10 MHz - 14 MHz
C	1.8 MHz - 1.9 MHz
D	220 MHz - 450 MHz

14. - E3B03

What is the best time of day for transequatorial propagation?

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

15. - E3C05

What orientation of Bz (B sub z) increases the likelihood that incoming particles from the sun will cause disturbed conditions?

Select	Answer
A	Eastward
B	Westward
C	Northward
D	Southward

16. - E4A02

Which of the following parameters does a spectrum analyzer display on the vertical and horizontal axes?

Select	Answer
A	SWR and time
B	SWR and frequency
C	RF amplitude and time
D	RF amplitude and frequency

17. - E4B02

What is the significance of voltmeter sensitivity expressed in ohms per volt?

Select	Answer
A	When used as an ohmmeter, the reading in ohms divided by the ohms per volt rating will determine the voltage applied to the circuit
B	When used as an ammeter, the full scale reading in amps divided by ohms per volt rating will determine the size of shunt needed
C	When used as a galvanometer, the reading in volts multiplied by the ohms per volt rating will determine the power drawn by the device under test
D	The full scale reading of the voltmeter multiplied by its ohms per volt rating will indicate the input impedance of the voltmeter

18. - E4C11

Why can an attenuator be used to reduce receiver overload on the lower frequency HF bands with little or no impact on signal-to-noise ratio?

Select	Answer
A	The attenuator has a low-pass filter to increase the strength of lower frequency signals
B	The attenuator has a noise filter to suppress interference
C	Atmospheric noise is generally greater than internally generated noise even after attenuation
D	Signals are attenuated separately from the noise

19. - E4D07

Which of the following reduces the likelihood of receiver desensitization?

Select	Answer
A	Raise the receiver IF frequency
B	Increase the receiver front end gain
C	Decrease the RF bandwidth of the receiver
D	Switch from fast AGC to slow AGC

20. - E4E02

Which of the following types of noise can often be reduced with a digital signal processing noise filter?

Select	Answer
A	Power line noise
B	Ignition noise
C	All these choices are correct
D	Broadband white noise

21. - E5A13

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

Select	Answer
A	Phase shift can become uncontrolled
B	Internal voltages increase
C	Parasitic effects are minimized
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	68.2 degrees with the voltage lagging the current
B	68.2 degrees with the voltage leading the current
C	14.0 degrees with the voltage lagging the current
D	14.0 degrees with the voltage leading the current

23. - E5C12

Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and a 19-picofarad capacitor at 21.200 MHz?

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

24. - E5D03

What is microstrip?

Select	Answer
A	Precision printed circuit conductors above a ground plane that provide constant impedance interconnects at microwave frequencies
B	Short lengths of coax mounted on printed circuit boards to minimize time delay between microwave circuits
C	Miniature coax used for low power applications
D	Lightweight transmission line made of common zip cord

25. - E6A03

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

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

26. - E6B10

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

Select	Answer
A	6
B	1
C	7
D	5

27. - E6C07

What best describes a pull-up or pull-down resistor?

Select	Answer
A	A resistor in a keying circuit used to reduce key clicks
B	A resistor that ensures that an oscillator frequency does not drift
C	A resistor connected to the positive or negative supply line used to establish a voltage when an input or output is an open circuit
D	A resistor connected to an op-amp output that prevents signals from exceeding the power supply voltage

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

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

30. - E6F06

Which of these materials is most commonly used to create photoconductive devices?

Select	Answer
A	A crystalline semiconductor
B	A heavy metal
C	A liquid semiconductor
D	An ordinary metal

31. - E7A02

What is the function of a decade counter?

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

32. - E7B11

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

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

33. - E7C05

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

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

34. - E7D09

What is the main reason to use a charge controller with a solar power system?

Select	Answer
A	Prevention of battery damage due to overcharge
B	Control of electrolyte levels during battery discharge
C	Matching of day and night charge rates
D	Prevention of battery undercharge

35. - E7E03

What is a frequency discriminator stage in a FM receiver?

Select	Answer
A	An FM generator circuit
B	A circuit for detecting FM signals
C	An automatic band-switching circuit
D	A circuit for filtering two closely adjacent signals

36. - E7F06

What is the minimum number of bits required for an analog-to-digital converter to sample a signal with a range of 1 volt at a resolution of 1 millivolt?

Select	Answer
A	8 bits
B	6 bits
C	10 bits
D	4 bits

37. - E7G08

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

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

38. - E7H02

What is a microphonic?

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

39. - E8A10

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

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

40. - E8B10

What is frequency division multiplexing?

Select	Answer
A	Two or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter
B	The transmitted signal jumps from band to band at a predetermined rate
C	The transmitted signal is divided into packets of information
D	Two or more information streams are merged into a baseband, which then modulates the transmitter

41. - E8C08

How does ARQ accomplish error correction?

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

42. - E8D05

What is the most common method of reducing key clicks?

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

43. - E9A04

Which of the following factors affect the feed point impedance of an antenna?

Select	Answer
A	Transmission line length
B	The input power level
C	Antenna height
D	The settings of an antenna tuner at the transmitter

44. - E9B02

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

Select	Answer
A	14 dB
B	18 dB
C	36 dB
D	24 dB

45. - E9C05

Which of the following is a type of OCFD antenna?

Select	Answer
A	A remotely tunable dipole antenna using orthogonally controlled frequency diversity
B	A multiband dipole antenna using one-way circular polarization for frequency diversity
C	A dipole fed approximately 1/3 the way from one end with a 4:1 balun to provide multiband operation
D	A folded dipole center-fed with 300-ohm transmission line

46. - E9D12

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

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

47. - E9E06

Which of these feed line impedances would be suitable for constructing a quarter-wave Q-section for matching a 100-ohm loop to 50-ohm feed line?

Select	Answer
A	450 ohms
B	62 ohms
C	50 ohms
D	75 ohms

48. - E9F09

What is the approximate physical length of a foam polyethylene dielectric coaxial transmission line that is electrically 1/4 wavelength long at 7.2 MHz?

Select	Answer
A	10.4 meters
B	8.3 meters
C	5.2 meters
D	6.9 meters

49. - E9G03

Which of the following is often determined using a Smith chart?

Select	Answer
A	Impedance and SWR values in transmission lines
B	Beam headings and radiation patterns
C	Satellite azimuth and elevation bearings
D	Trigonometric functions

50. - E9H09

What is a Pennant antenna?

Select	Answer
A	A small, vertically oriented receiving antenna consisting of a triangular loop terminated in approximately 900 ohms
B	A stealth antenna built to look like a flagpole
C	A form of rhombic antenna terminated in a variable capacitor to provide frequency diversity
D	A four-element, high-gain vertical array invented by George Pennant

Figure E5-1

Figure E6-2

Figure E7-1

Figure E9-1