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

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1. - E0A08

What does SAR measure?

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

2. - E1A06

Where must the carrier frequency of a CW signal be set to comply with FCC rules for 60 meter operation?

Select	Answer
A	At the highest frequency of the channel
B	At the center frequency of the channel
C	On any frequency where the signal's sidebands are within the channel
D	At the lowest frequency of the channel

3. - E1B03

Within what distance must an amateur station protect an FCC monitoring facility from harmful interference?

Select	Answer
A	30 miles
B	10 miles
C	1 mile
D	3 miles

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	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
B	Operators may not operate until a test signal has been transmitted in coordination with the local power company
C	Operations may commence immediately, and may continue unless interference is reported by the UTC
D	Operators must not operate until approval is received

5. - E1D12

Which of the following amateur stations may transmit one-way communications?

Select	Answer
A	A message forwarding station or automatically controlled digital station
B	A local repeater or linked repeater station
C	A space station, beacon station, or telecommand station
D	All these choices are correct

6. - E1E01

For which types of out-of-pocket expenses do the Part 97 rules state that VEs and VECs may be reimbursed?

Select	Answer
A	Providing amateur operator license examination preparation training materials
B	No expenses are authorized for reimbursement
C	Preparing, processing, administering, and coordinating an examination for an amateur radio operator license
D	Teaching an amateur operator license examination preparation course

7. - E1F07

When may an amateur station send a message to a business?

Select	Answer
A	When neither the amateur nor his or her employer has a pecuniary interest in the communications
B	When the control operator is employed by the FCC or another government agency
C	When the total money involved does not exceed $25
D	When transmitting international third-party communications

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. - E2B01

How many times per second is a new frame transmitted in a fast-scan (NTSC) television system?

Select	Answer
A	120
B	30
C	60
D	90

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	An automatic method for rapidly zero beating or tuning to a station's frequency before calling that station
C	The acceptable practice of manually posting the call signs of stations on a spotting network
D	A manual technique for rapidly zero beating or tuning to a station's frequency before calling that station

11. - E2D10

How can an APRS station be used to help support a public service communications activity?

Select	Answer
A	An APRS station with a Global Positioning System unit can automatically transmit information to show a mobile station's position during the event
B	An APRS station with an emergency medical technician can automatically transmit medical data to the nearest hospital
C	All these choices are correct
D	APRS stations with General Personnel Scanners can automatically relay the participant numbers and time as they pass the check points

12. - E2E10

Which of these digital modes has the narrowest bandwidth?

Select	Answer
A	PSK31
B	300-baud packet
C	170 Hz shift, 45-baud RTTY
D	MFSK16

13. - E3A13

Which of these emission modes is best for auroral propagation?

Select	Answer
A	CW
B	FM
C	RTTY
D	SSB

14. - E3B06

Which of the following amateur bands most frequently provides long-path propagation?

Select	Answer
A	10 meters
B	20 meters
C	6 meters
D	80 meters

15. - E3C13

What type of polarization is best for ground-wave propagation?

Select	Answer
A	Elliptical
B	Horizontal
C	Circular
D	Vertical

16. - E4A10

Which of the following displays multiple digital signal states simultaneously?

Select	Answer
A	Logic analyzer
B	Modulation monitor
C	Network analyzer
D	Bit error rate tester

17. - E4B03

Which S parameter is equivalent to forward gain?

Select	Answer
A	S22
B	S12
C	S21
D	S11

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	Signals are attenuated separately from the noise
C	The attenuator has a noise filter to suppress interference
D	Atmospheric noise is generally greater than internally generated noise even after attenuation

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 third-order intercept point
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 level of an incoming signal that will cause 1 dB of gain compression

20. - E4E06

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

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

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. - E5B11

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 25 ohms, R is 100 ohms, and XL is 50 ohms?

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

23. - E5C04

What coordinate system is often used to display the resistive, inductive, and/or capacitive reactance components of impedance?

Select	Answer
A	Elliptical coordinates
B	Maidenhead grid
C	Rectangular coordinates
D	Faraday grid

24. - E5D11

What is the power factor of an RL circuit having a 60-degree phase angle between the voltage and the current?

Select	Answer
A	1.73
B	0.866
C	1.414
D	0.5

25. - E6A04

What is the name given to an impurity atom that adds holes to a semiconductor crystal structure?

Select	Answer
A	Donor impurity
B	N-type impurity
C	Acceptor impurity
D	Insulator impurity

26. - E6B06

Which of the following is a common use of a Schottky diode?

Select	Answer
A	As a rectifier in high current power supplies
B	As a VHF/UHF mixer or detector
C	As a variable capacitance in an automatic frequency control circuit
D	As a constant voltage reference in a power supply

27. - E6C03

What is tri-state logic?

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

28. - E6D06

What core material property determines the inductance of an inductor?

Select	Answer
A	Reactivity
B	Permeability
C	Resistance
D	Thermal impedance

29. - E6E07

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

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

30. - E6F11

What is the approximate open-circuit voltage produced by a fully illuminated silicon photovoltaic cell?

Select	Answer
A	0.1 V
B	0.5 V
C	1.5 V
D	12 V

31. - E7A03

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

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

32. - E7B13

Which of the following describes an emitter follower (or common collector) amplifier?

Select	Answer
A	An OR circuit with only one emitter used for output
B	An amplifier with a low impedance output that follows the base input voltage
C	A two-transistor amplifier with the emitters sharing a common bias resistor
D	A differential amplifier with both inputs fed to the emitter of the input transistor

33. - E7C01

How are the capacitors and inductors of a low-pass filter Pi-network arranged between the network's input and output?

Select	Answer
A	Two capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground
B	Two inductors are in series between the input and output, and a capacitor is connected between the two inductors and ground
C	A capacitor is connected between the input and ground, another capacitor is connected between the output and ground, and an inductor is connected between input and output
D	An inductor is connected between the input and ground, another inductor is connected between the output and ground, and a capacitor is connected between the input and output

34. - E7D08

What type of circuit is shown in Figure E7-2?

Select	Answer
A	Grounded emitter amplifier
B	Switching voltage regulator
C	Linear voltage regulator
D	Monostable multivibrator

35. - E7E07

What is meant by the term "baseband" in radio communications?

Select	Answer
A	The frequency range occupied by a message signal prior to modulation
B	The basic oscillator frequency in an FM transmitter that is multiplied to increase the deviation and carrier frequency
C	The lowest frequency band that the transmitter or receiver covers
D	The unmodulated bandwidth of the transmitted signal

36. - E7F04

What is a common method of generating an SSB signal using digital signal processing?

Select	Answer
A	Varying quartz crystal characteristics emulated in digital form
B	Mixing products are converted to voltages and subtracted by adder circuits
C	A frequency synthesizer removes the unwanted sidebands
D	Signals are combined in quadrature phase relationship

37. - E7G03

What is the typical input impedance of an op-amp?

Select	Answer
A	Very low
B	100 ohms
C	1000 ohms
D	Very high

38. - E7H14

What is a phase-locked loop circuit?

Select	Answer
A	An electronic circuit also known as a monostable multivibrator
B	An electronic servo loop consisting of a phase detector, a low-pass filter, a voltage-controlled oscillator, and a stable reference oscillator
C	An electronic circuit consisting of a precision push-pull amplifier with a differential input
D	An electronic servo loop consisting of a ratio detector, reactance modulator, and voltage-controlled oscillator

39. - E8A03

What type of wave does a Fourier analysis show to be made up of sine waves of a given fundamental frequency plus all its harmonics?

Select	Answer
A	A sawtooth wave
B	A sine wave
C	A cosine wave
D	A square wave

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	1/3
B	3
C	6000
D	2000

41. - E8C11

What is the relationship between symbol rate and baud?

Select	Answer
A	Symbol rate is only used for packet-based modes
B	Baud is only used for RTTY
C	Baud is twice the symbol rate
D	They are the same

42. - E8D08

What parameter evaluates distortion of an AFSK signal caused by excessive input audio levels?

Select	Answer
A	Signal-to-noise ratio
B	Intermodulation Distortion (IMD)
C	Baud rate
D	Repeat Request Rate (RRR)

43. - E9A11

Which of the following factors determines ground losses for a ground-mounted vertical antenna operating in the 3 MHz to 30 MHz range?

Select	Answer
A	The standing wave ratio
B	Distance from the transmitter
C	Soil conductivity
D	Take-off angle

44. - E9B08

What is the far field of an antenna?

Select	Answer
A	The region where radiated power dissipates over a specified time period
B	The region where radiated field strengths are constant
C	The region of the ionosphere where radiated power is not refracted
D	The region where the shape of the antenna pattern is independent of distance

45. - E9C05

Which of the following is a type of OCFD antenna?

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

46. - E9D03

Where should a high Q loading coil be placed to minimize losses in a shortened vertical antenna?

Select	Answer
A	As close to the transmitter as possible
B	As low as possible on the vertical radiator
C	Near the center of the vertical radiator
D	At a voltage node

47. - E9E04

What is the purpose of the series capacitor in a gamma-type antenna matching network?

Select	Answer
A	To provide a rejection notch that prevents the radiation of harmonics
B	To provide DC isolation between the feed line and the antenna
C	To cancel the inductive reactance of the matching network
D	To transform the antenna impedance to a higher value

48. - E9F10

What impedance does a 1/8-wavelength transmission line present to a generator when the line is shorted at the far end?

Select	Answer
A	An inductive reactance
B	The same as the characteristic impedance of the line
C	A capacitive reactance
D	Zero

49. - E9G04

What are the two families of circles and arcs that make up a Smith chart?

Select	Answer
A	Resistance and voltage
B	Voltage and impedance
C	Resistance and reactance
D	Reactance and voltage

50. - E9H08

What is the function of a sense antenna?

Select	Answer
A	It allows DF antennas to receive signals at different vertical angles
B	It increases the sensitivity of a DF antenna array
C	It modifies the pattern of a DF antenna array to provide a null in one direction
D	It provides diversity reception that cancels multipath signals

Figure E7-2