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

Logging in (or registering) will help the system to select questions that you need to focus on.

1. - E1A07

Which amateur band requires transmission on specific channels rather than on a range of frequencies?

Select	Answer
A	60 meter band
B	12 meter band
C	30 meter band
D	17 meter band

2. - E1B10

What frequencies are authorized to an amateur station operating under RACES rules?

Select	Answer
A	Military Auxiliary Radio System (MARS) channels
B	Specific segments in the amateur service MF, HF, VHF and UHF bands
C	All amateur service frequencies authorized to the control operator
D	Specific local government channels

3. - E1C03

How do the control operator responsibilities of a station under automatic control differ from one under local control?

Select	Answer
A	Under local control a control operator is not required to be present at a control point
B	Under local control there is no control operator
C	Under automatic control there is no control operator
D	Under automatic control the control operator is not required to be present at the control point

4. - E1D05

What class of licensee is authorized to be the control operator of a space station?

Select	Answer
A	Only Amateur Extra Class
B	Any class with appropriate operator privileges
C	All except Technician Class
D	Only General, Advanced or Amateur Extra Class

5. - E1E04

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

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

6. - E1F11

Which of the following best describes one of the standards that must be met by an external RF power amplifier if it is to qualify for a grant of FCC certification?

Select	Answer
A	It must produce full legal output when driven by not more than 5 watts of mean RF input power
B	It must satisfy the FCC's spurious emission standards when operated at the lesser of 1500 watts or its full output power
C	It must exhibit a gain of 0 dB or less over its full output range
D	It must be capable of external RF switching between its input and output networks

7. - E2A04

What is meant by the term mode as applied to an amateur radio satellite?

Select	Answer
A	The type of signals that can be relayed through the satellite
B	The satellite's orientation with respect to the Earth
C	Whether the satellite is in a polar or equatorial orbit
D	The satellite's uplink and downlink frequency bands

8. - E2B01

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

Select	Answer
A	60
B	30
C	120
D	90

9. - E2C02

Which of the following best describes the term self-spotting in regards to HF contest operating?

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

10. - E2D08

What type of packet frame is used to transmit APRS beacon data?

Select	Answer
A	Connect
B	Unnumbered Information
C	Disconnect
D	Acknowledgement

11. - E2E03

How is the timing of JT65 contacts organized?

Select	Answer
A	It depends on the lunar phase
B	Stations take turns on alternate days
C	Alternating transmissions at 1 minute intervals
D	By exchanging ACK/NAK packets

12. - E3A09

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

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

13. - E3B08

What type of HF propagation is probably occurring if radio signals travel along the terminator between daylight and darkness?

Select	Answer
A	Gray-line
B	Long-path
C	Sporadic-E
D	Transequatorial

14. - E3C01

What does the term ray tracing describe in regard to radio communications?

Select	Answer
A	The process in which an electronic display presents a pattern
B	Modeling a radio wave's path through the ionosphere
C	Determining the radiation pattern from an array of antennas
D	Evaluating high voltage sources for X-Rays

15. - E4A07

Which of the following is an advantage of using an antenna analyzer compared to an SWR bridge to measure antenna SWR?

Select	Answer
A	Antenna analyzers automatically tune your antenna for resonance
B	Antenna analyzers display a time-varying representation of the modulation envelope
C	Antenna analyzers do not need an external RF source
D	All of these choices are correct

16. - E4B16

Which S parameter represents return loss or SWR?

Select	Answer
A	S11
B	S12
C	S21
D	S22

17. - E4C01

What is an effect of excessive phase noise in the local oscillator section of a receiver?

Select	Answer
A	It can cause strong signals on nearby frequencies to interfere with reception of weak signals
B	It decreases receiver third-order intermodulation distortion dynamic range
C	It limits the receiver's ability to receive strong signals
D	It reduces receiver sensitivity

18. - E4D13

Which of the following can cause receiver desensitization?

Select	Answer
A	Squelch gain misadjusted
B	Audio bias adjusted too high
C	Audio gain adjusted too low
D	Strong adjacent channel signals

19. - E4E05

How can noise from an electric motor be suppressed?

Select	Answer
A	By using a ground-fault current interrupter in the circuit used to power the motor
B	By installing a high pass filter in series with the motor's power leads
C	By installing a brute-force AC-line filter in series with the motor leads
D	By installing a bypass capacitor in series with the motor leads

20. - E5A06

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

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

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

22. - E5C08

What coordinate system is often used to display the phase angle of a circuit containing resistance, inductive and/or capacitive reactance?

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

23. - E5D16

What is the power factor of an R-L circuit having a 30 degree phase angle between the voltage and the current?

Select	Answer
A	0.577
B	1.73
C	0.866
D	0.5

24. - E6A02

Which of the following semiconductor materials contains excess free electrons?

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

25. - E6B12

What is one common use for PIN diodes?

Select	Answer
A	As an RF switch
B	As a constant voltage source
C	As a constant current source
D	As a high voltage rectifier

26. - E6C04

What is the primary advantage of tri-state logic?

Select	Answer
A	High speed operation
B	Ability to connect many device outputs to a common bus
C	More efficient arithmetic operations
D	Low power consumption

27. - E6D07

What is the usable frequency range of inductors that use toroidal cores, assuming a correct selection of core material for the frequency being used?

Select	Answer
A	From approximately 10 Hz to no more than 3000 kHz
B	From about 100 kHz to at least 1000 GHz
C	From less than 20 Hz to approximately 300 MHz
D	From a few kHz to no more than 30 MHz

28. - E6E05

Which of the following noise figure values is typical of a low-noise UHF preamplifier?

Select	Answer
A	-20 dBm
B	-10 dB
C	44 dBm
D	2 dB

29. - E6F10

What is the most common type of photovoltaic cell used for electrical power generation?

Select	Answer
A	Selenium
B	Cadmium Sulfide
C	Silicon
D	Copper oxide

30. - E7A02

What is the function of a decade counter digital IC?

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

31. - E7B10

In Figure E7-1, what is the purpose of R1 and R2?

Select	Answer
A	Fixed bias
B	Self bias
C	Feedback
D	Load resistors

32. - E7C12

Which describes a Pi-L-network used for matching a vacuum tube final amplifier to a 50 ohm unbalanced output?

Select	Answer
A	A matching network in which all components are isolated from ground
B	A Phase Inverter Load network
C	A network with only three discrete parts
D	A Pi-network with an additional series inductor on the output

33. - E7D14

What is one purpose of a "bleeder" resistor in a conventional unregulated power supply?

Select	Answer
A	To boost the amount of output current
B	To improve output voltage regulation
C	To cut down on waste heat generated by the power supply
D	To balance the low-voltage filament windings

34. - E7E10

How does a diode detector function?

Select	Answer
A	By mixing signals with noise in the transition region of the diode
B	By sensing the change of reactance in the diode with respect to frequency
C	By rectification and filtering of RF signals
D	By breakdown of the Zener voltage

35. - E7F03

What type of digital signal processing filter is used to generate an SSB signal?

Select	Answer
A	A Hilbert-transform filter
B	An elliptical filter
C	An adaptive filter
D	A notch filter

36. - E7G01

What is the typical output impedance of an integrated circuit op-amp?

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

37. - E7H14

What is a phase-locked loop circuit?

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

38. - E8A10

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

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

39. - 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	2000
B	1/3
C	6000
D	3

40. - E8C04

What technique is used to minimize the bandwidth requirements of a PSK31 signal?

Select	Answer
A	Use of sinusoidal data pulses
B	Zero-sum character encoding
C	Reed-Solomon character encoding
D	Use of trapezoidal data pulses

41. - E8D09

What is considered a good minimum IMD level for an idling PSK signal?

Select	Answer
A	+10 dB
B	-30 dB
C	-20 dB
D	+15 dB

42. - E9A08

What is meant by antenna bandwidth?

Select	Answer
A	Antenna length divided by the number of elements
B	The angle between the half-power radiation points
C	The frequency range over which an antenna satisfies a performance requirement
D	The angle formed between two imaginary lines drawn through the element ends

43. - E9B08

How can the approximate beam-width in a given plane of a directional antenna be determined?

Select	Answer
A	Measure the ratio of the signal strengths of the radiated power lobes from the front and side of the antenna
B	Measure the ratio of the signal strengths of the radiated power lobes from the front and rear of the antenna
C	Draw two imaginary lines through the ends of the elements and measure the angle between the lines
D	Note the two points where the signal strength of the antenna is 3 dB less than maximum and compute the angular difference

44. - E9C06

What is the effect of a terminating resistor on a rhombic antenna?

Select	Answer
A	It changes the radiation pattern from horizontal to vertical polarization
B	It changes the radiation pattern from bidirectional to unidirectional
C	It decreases the ground loss
D	It reflects the standing waves on the antenna elements back to the transmitter

45. - E9D06

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

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

46. - E9E01

What system matches a higher impedance transmission line to a lower impedance antenna by connecting the line to the driven element in two places spaced a fraction of a wavelength each side of element center?

Select	Answer
A	The stub matching system
B	The delta matching system
C	The omega matching system
D	The gamma matching system

47. - E9F07

How does ladder line compare to small-diameter coaxial cable such as RG-58 at 50 MHz?

Select	Answer
A	Lower loss
B	Lower velocity factor
C	Higher SWR
D	Smaller reflection coefficient

48. - E9G03

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

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

49. - E9H11

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

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

50. - E0A08

What does SAR measure?

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

Figure E7-1