US Amateur Radio - Amateur Extra (Element 4, 2016-2020) Practice Test

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1. - E1A03

With your transceiver displaying the carrier frequency of phone signals, you hear a station calling CQ on 14.349 MHz USB. Is it legal to return the call using upper sideband on the same frequency?

Select	Answer
A	Yes, because the displayed frequency is within the 20 meter band
B	Yes, because you were not the station calling CQ
C	No, U.S. stations are not permitted to use phone emissions above 14.340 MHz
D	No, the sideband will extend beyond the band edge

2. - E1B05

What is the National Radio Quiet Zone?

Select	Answer
A	An area in Puerto Rico surrounding the Arecibo Radio Telescope
B	An area in New Mexico surrounding the White Sands Test Area
C	An area in Florida surrounding Cape Canaveral
D	An area surrounding the National Radio Astronomy Observatory

3. - E1C08

What is the maximum permissible duration of a remotely controlled station's transmissions if its control link malfunctions?

Select	Answer
A	5 minutes
B	3 minutes
C	10 minutes
D	30 seconds

4. - E1D11

Which amateur stations are eligible to operate as Earth stations?

Select	Answer
A	Only those of General, Advanced or Amateur Extra Class operators
B	Only those of Amateur Extra Class operators
C	Any amateur station, subject to the privileges of the class of operator license held by the control operator
D	Any amateur station whose licensee has filed a pre-space notification with the FCC's International Bureau

5. - E1E05

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

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

6. - 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. Extra Class privileges
B	All privileges of the Extra Class license
C	None, they must obtain a U.S. license
D	Full privileges, up to and including those of the Extra Class License, on the 80, 40, 20, 15, and 10 meter bands

7. - E2A14

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

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

8. - E2B07

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

Select	Answer
A	Hue
B	Luminance
C	Spectral Intensity
D	Chroma

9. - E2C01

Which of the following is true about contest operating?

Select	Answer
A	Interference to other amateurs is unavoidable and therefore acceptable
B	Operators are permitted to make contacts even if they do not submit a log
C	Every contest requires a signal report in the exchange
D	It is mandatory to transmit the call sign of the station being worked as part of every transmission to that station

10. - E2D06

Which of the following describes a method of establishing EME contacts?

Select	Answer
A	Time synchronous transmissions alternately from each station
B	High speed CW identification to avoid fading
C	Storing and forwarding digital messages
D	Judging optimum transmission times by monitoring beacons reflected from the Moon

11. - E2E12

Which type of control is used by stations using the Automatic Link Enable (ALE) protocol?

Select	Answer
A	Remote
B	Automatic
C	Local
D	ALE can use any type of control

12. - E3A16

Which of the following best describes electromagnetic waves traveling in free space?

Select	Answer
A	The waves are reflected by the ionosphere and return to their source
B	Electric and magnetic fields become aligned as they travel
C	Changing electric and magnetic fields propagate the energy
D	The energy propagates through a medium with a high refractive index

13. - E3B05

Which amateur bands typically support long-path propagation?

Select	Answer
A	6 meters to 2 meters
B	160 meters to 40 meters
C	30 meters to 10 meters
D	160 meters to 10 meters

14. - E3C06

By how much does the VHF/UHF radio horizon distance exceed the geometric horizon?

Select	Answer
A	By approximately four times the distance
B	By approximately 50 percent of the distance
C	By approximately twice the distance
D	By approximately 15 percent of the distance

15. - E4A01

Which of the following parameter determines the bandwidth of a digital or computer-based oscilloscope?

Select	Answer
A	Input capacitance
B	Input impedance
C	Sample resolution
D	Sampling rate

16. - E4B08

Which of the following is a characteristic of a good DC voltmeter?

Select	Answer
A	High reluctance input
B	Low reluctance input
C	High impedance input
D	Low impedance input

17. - E4C17

Which of the following has the largest effect on an SDR receiver's linearity?

Select	Answer
A	Anti-aliasing input filter bandwidth
B	Analog-to-digital converter sample width in bits
C	RAM speed used for data storage
D	CPU register width in bits

18. - E4D12

What is the term for the reduction in receiver sensitivity caused by a strong signal near the received frequency?

Select	Answer
A	Desensitization
B	Squelch gain rollback
C	Cross-modulation interference
D	Quieting

19. - E4E03

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

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

20. - E5A01

What can cause the voltage across reactances in series to be larger than the voltage applied to them?

Select	Answer
A	Resistance
B	Capacitance
C	Conductance
D	Resonance

21. - E5B01

What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the applied voltage?

Select	Answer
A	One time constant
B	A time factor of one
C	An exponential rate of one
D	One exponential period

22. - E5C01

Which of the following represents a capacitive reactance in rectangular notation?

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

23. - E5D06

In what direction is the magnetic field oriented about a conductor in relation to the direction of electron flow?

Select	Answer
A	In a direction determined by the left-hand rule
B	In all directions; omni-directional
C	In the same direction as the current
D	In a direction opposite to the current

24. - E6A09

What is a depletion-mode FET?

Select	Answer
A	An FET that exhibits a current flow between source and drain when no gate voltage is applied
B	Any FET for which holes are the majority carriers
C	An FET that has no current flow between source and drain when no gate voltage is applied
D	Any FET without a channel

25. - E6B06

Which of the following is a common use of a hot-carrier diode?

Select	Answer
A	As a variable capacitance in an automatic frequency control circuit
B	As a constant voltage reference in a power supply
C	As balanced mixers in FM generation
D	As a VHF/UHF mixer or detector

26. - E6C06

Why do CMOS digital integrated circuits have high immunity to noise on the input signal or power supply?

Select	Answer
A	The input switching threshold is about one-half the power supply voltage
B	Input signals are stronger
C	The input switching threshold is about two times the power supply voltage
D	Larger bypass capacitors are used in CMOS circuit design

27. - E6D09

What devices are commonly used as VHF and UHF parasitic suppressors at the input and output terminals of a transistor HF amplifier?

Select	Answer
A	Butterworth filters
B	Electrolytic capacitors
C	Ferrite beads
D	Steel-core toroids

28. - E6E12

Why are high-power RF amplifier ICs and transistors sometimes mounted in ceramic packages?

Select	Answer
A	High-voltage insulating ability
B	Enhanced sensitivity to light
C	Better dissipation of heat
D	To provide a low-pass frequency response

29. - E6F09

What is the efficiency of a photovoltaic cell?

Select	Answer
A	The relative fraction of light that is converted to current
B	The output RF power divided by the input DC power
C	The effective payback period
D	The open-circuit voltage divided by the short-circuit current under full illumination

30. - E7A02

What is the function of a decade counter digital IC?

Select	Answer
A	It decodes a decimal number for display on a seven segment LED display
B	It adds two decimal numbers together
C	It produces one output pulse for every ten input pulses
D	It produces ten output pulses for every input pulse

31. - E7B16

What is the effect of intermodulation products in a linear power amplifier?

Select	Answer
A	Low efficiency
B	Creation of parasitic oscillations
C	Transmission of spurious signals
D	All of these choices are correct

32. - 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	A passive op-amp filter
D	An active LC filter

33. - E7D07

What is the purpose of C2 in the circuit shown in Figure E7-3?

Select	Answer
A	To self-resonate at the hum frequency
B	It is a brute force filter for the output
C	It bypasses hum around D1
D	To provide fixed DC bias for Q1

34. - E7E06

Why is de-emphasis commonly used in FM communications receivers?

Select	Answer
A	To reduce impulse noise reception
B	For higher efficiency
C	For compatibility with transmitters using phase modulation
D	To remove third-order distortion products

35. - E7F17

What do the letters I and Q in I/Q Modulation represent?

Select	Answer
A	Inactive and Quiescent
B	Instantaneous and Quenched
C	In-phase and Quadrature
D	Instantaneous and Quasi-stable

36. - E7G06

Which of the following is the most appropriate use of an op-amp active filter?

Select	Answer
A	For smoothing power supply output
B	As a high-pass filter used to block RFI at the input to receivers
C	As a low-pass filter used between a transmitter and a transmission line
D	As an audio filter in a receiver

37. - E7H02

Which describes a microphonic?

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

38. - E8A01

What is the name of the process that shows that a square wave is made up of a sine wave plus all of its odd harmonics?

Select	Answer
A	Numerical analysis
B	Vector analysis
C	Fourier analysis
D	Differential analysis

39. - E8B02

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

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

40. - E8C08

How does ARQ accomplish error correction?

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

41. - E8D10

What are some of the differences between the Baudot digital code and ASCII?

Select	Answer
A	Baudot uses 6 data bits per character, ASCII uses 7 or 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes
B	Baudot uses 4 data bits per character, ASCII uses 7 or 8; Baudot uses 1 character as a letters/figures shift code, ASCII has no letters/figures code
C	Baudot uses 7 data bits per character, ASCII uses 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes
D	Baudot uses 5 data bits per character, ASCII uses 7 or 8; Baudot uses 2 characters as letters/figures shift codes, ASCII has no letters/figures shift code

42. - E9A07

What is meant by antenna gain?

Select	Answer
A	The ratio of the signal in the forward direction to that in the opposite direction
B	The ratio of the amount of power radiated by an antenna compared to the transmitter output power
C	The final amplifier gain minus the transmission line losses
D	The ratio of the radiated signal strength of an antenna in the direction of maximum radiation to that of a reference antenna

43. - E9B16

How many elevation lobes appear in the forward direction of the antenna radiation pattern shown in Figure E9-2?

Select	Answer
A	1
B	7
C	3
D	4

44. - E9C13

What is the main effect of placing a vertical antenna over an imperfect ground?

Select	Answer
A	It causes increased SWR
B	It reduces low-angle radiation
C	It reduces losses in the radiating portion of the antenna
D	It changes the impedance angle of the matching network

45. - E9D06

What happens to the bandwidth of an antenna as it is shortened through the use of loading coils?

Select	Answer
A	It is increased
B	No change occurs
C	It becomes flat
D	It is decreased

46. - E9E07

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

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

47. - E9F13

What impedance does a 1/4 wavelength transmission line present to a generator when the line is shorted at the far end?

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

48. - E9G03

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

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

49. - E9H11

What characteristic of a cardioid pattern antenna is useful for direction finding?

Select	Answer
A	Broad band response
B	A very sharp peak
C	High-radiation angle
D	A very sharp single null

50. - E0A06

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

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

Figure E7-3

Figure E9-2