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

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1. - E0A05

What is one of the potential hazards of operating in the amateur radio microwave bands?

Select	Answer
A	The extremely high frequency energy can damage the joints of antenna structures
B	Microwaves often travel long distances by ionospheric reflection
C	The high gain antennas commonly used can result in high exposure levels
D	Microwaves are ionizing radiation

2. - E1A13

Who must be in physical control of the station apparatus of an amateur station aboard any vessel or craft that is documented or registered in the United States?

Select	Answer
A	Only a person with an FCC Marine Radio license grant
B	Only a person named in an amateur station license grant
C	Any person holding an FCC issued amateur license or who is authorized for alien reciprocal operation
D	Any person named in an amateur station license grant or a person holding an unrestricted Radiotelephone Operator Permit

3. - E1B07

To what type of regulations does PRB-1 apply?

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

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

5. - E1D07

Which HF amateur bands have frequencies authorized for space stations?

Select	Answer
A	All HF bands
B	Only the 40, 20, 17, 15, and 10 meter bands
C	Only the 40, 30, 20, 15, 12, and 10 meter bands
D	Only the 40, 20, 17, 15, 12, and 10 meter bands

6. - E1E02

Who does Part 97 task with maintaining the pools of questions for all U.S. amateur license examinations?

Select	Answer
A	The VECs
B	The VEs
C	The ARRL
D	The FCC

7. - E1F03

Under what circumstances may a dealer sell an external RF power amplifier capable of operation below 144 MHz if it has not been granted FCC certification?

Select	Answer
A	The equipment dealer assembled it from a kit
B	It was purchased in used condition from an amateur operator and is sold to another amateur operator for use at that operator's station
C	It was imported from a manufacturer in another country and was certificated by that country's government
D	It was imported from a manufacturer in a country that does not require certification of RF power amplifiers

8. - E2A06

What are Keplerian elements?

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

9. - E2B10

What aspect of an analog slow-scan television signal encodes the brightness of the picture?

Select	Answer
A	Sync amplitude
B	Sync frequency
C	Tone amplitude
D	Tone frequency

10. - E2C02

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

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

11. - E2D06

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

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

12. - E2E08

Which of the following HF digital modes can be used to transfer binary files?

Select	Answer
A	AMTOR
B	Hellschreiber
C	RTTY
D	PACTOR

13. - E3A09

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

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

14. - E3B03

What is the best time of day for transequatorial propagation?

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

15. - E3C07

Which of the following descriptors indicates the greatest solar flare intensity?

Select	Answer
A	Class A
B	Class X
C	Class M
D	Class B

16. - E4A10

Which of the following displays multiple digital signal states simultaneously?

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

17. - E4B03

Which S parameter is equivalent to forward gain?

Select	Answer
A	S11
B	S21
C	S22
D	S12

18. - E4C01

What is an effect of excessive phase noise in a receiver's local oscillator?

Select	Answer
A	It decreases receiver third-order intercept point
B	It can affect the receiver's frequency calibration
C	It limits the receiver's ability to receive strong signals
D	It can combine with strong signals on nearby frequencies to generate interference

19. - E4D01

What is meant by the blocking dynamic range of a receiver?

Select	Answer
A	The minimum difference in dB between two signals which produce third-order intermodulation products greater than the noise floor
B	The difference in dB between the noise floor and the third-order intercept point
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. - E4E07

Which of the following can cause shielded cables to radiate or receive interference?

Select	Answer
A	Low inductance ground connections at both ends of the shield
B	Use of braided shielding material
C	Tying all ground connections to a common point resulting in differential-mode currents in the shield
D	Common-mode currents on the shield and conductors

21. - E5A15

Which of the following increases Q for inductors and capacitors?

Select	Answer
A	Higher self-resonant frequency
B	Lower losses
C	Lower self-resonant frequency
D	Lower reactance

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

23. - E5C09

When using rectangular coordinates to graph the impedance of a circuit, what do the axes represent?

Select	Answer
A	The X axis represents the phase angle and the Y axis represents the magnitude
B	The X axis represents the magnitude and the Y axis represents the phase angle
C	The X axis represents the reactive component and the Y axis represents the resistive component
D	The X axis represents the resistive component and the Y axis represents the reactive component

24. - E5D09

What happens to reactive power in an AC circuit that has both ideal inductors and ideal capacitors?

Select	Answer
A	It is dissipated in the formation of inductive and capacitive fields
B	It is dissipated as kinetic energy in the circuit
C	It is dissipated as heat in the circuit
D	It is repeatedly exchanged between the associated magnetic and electric fields, but is not dissipated

25. - E6A11

In Figure E6-1, what is the schematic symbol for a P-channel junction FET?

Select	Answer
A	3
B	6
C	1
D	2

26. - E6B07

What is the failure mechanism when a junction diode fails due to excessive current?

Select	Answer
A	Excessive junction temperature
B	Excessive inverse voltage
C	Insufficient forward voltage
D	Charge carrier depletion

27. - E6C01

What is the function of hysteresis in a comparator?

Select	Answer
A	To increase the sensitivity
B	To allow the comparator to be used with AC input signals
C	To prevent input noise from causing unstable output signals
D	To cause the output to change states continually

28. - E6D05

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

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

29. - E6E06

What characteristics of the MMIC make it a popular choice for VHF through microwave circuits?

Select	Answer
A	The ability to retrieve information from a single signal even in the presence of other strong signals
B	Controlled gain, low noise figure, and constant input and output impedance over the specified frequency range
C	Plate current that is controlled by a control grid
D	Nearly infinite gain, very high input impedance, and very low output impedance

30. - E6F06

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

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

31. - E7A08

What logical operation does an OR gate perform?

Select	Answer
A	It produces logic 1 at its output if all inputs are logic 0
B	It produces logic 1 at its output if any or all inputs are logic 1
C	It produces logic 0 at its output if all inputs are logic 1
D	It only produces logic 0 at its output when all inputs are logic 1

32. - E7B17

Why are odd-order rather than even-order intermodulation distortion products of concern in linear power amplifiers?

Select	Answer
A	Because they maintain the sidebands, thus causing multiple duplicate signals
B	Because they invert the sidebands causing distortion
C	Because they are relatively far in frequency from the desired signal
D	Because they are relatively close in frequency to the desired signal

33. - E7C07

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 network with only three discrete parts
C	A Phase Inverter Load network
D	A Pi-network with an additional series inductor on the output

34. - E7D01

How does a linear electronic voltage regulator work?

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

35. - E7E09

What occurs when an excessive amount of signal energy reaches a mixer circuit?

Select	Answer
A	Mixer blanking occurs
B	A beat frequency is generated
C	Spurious mixer products are generated
D	Automatic limiting occurs

36. - E7F14

Which of the following would allow a digital signal processing filter to create a sharper filter response?

Select	Answer
A	Higher data rate
B	Complex phasor representations
C	More taps
D	Double-precision math routines

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	38
B	0.03
C	76
D	1

38. - E7H10

What information is contained in the lookup table of a direct digital synthesizer (DDS)?

Select	Answer
A	The phase relationship between a voltage-controlled oscillator and the output waveform
B	Frequently used receiver and transmitter frequencies
C	The phase relationship between a reference oscillator and the output waveform
D	Amplitude values that represent the desired waveform

39. - E8A10

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

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

40. - E8B02

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

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

41. - E8C09

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

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

42. - E8D08

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

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

43. - E9A03

What is the radiation resistance of an antenna?

Select	Answer
A	The combined losses of the antenna elements and feed line
B	The value of a resistance that would dissipate the same amount of power as that radiated from an antenna
C	The specific impedance of the antenna
D	The resistance in the atmosphere that an antenna must overcome to be able to radiate a signal

44. - E9B04

What is the front-to-back ratio of the radiation pattern shown in Figure E92?

Select	Answer
A	15 dB
B	3 dB
C	28 dB
D	38 dB

45. - E9C10

Which of the following describes a Zepp antenna?

Select	Answer
A	An omni-directional antenna commonly used for satellite communications
B	An end-fed dipole antenna
C	A vertical array capable of quickly changing the direction of maximum radiation by changing phasing lines
D	A dipole constructed from zip cord

46. - E9D04

Why should an HF mobile antenna loading coil have a high ratio of reactance to resistance?

Select	Answer
A	To swamp out harmonics
B	To lower the radiation angle
C	To minimize the Q
D	To minimize losses

47. - E9E04

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

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

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	5.2 meters
B	10.4 meters
C	8.3 meters
D	6.9 meters

49. - E9G01

Which of the following can be calculated using a Smith chart?

Select	Answer
A	Radio propagation
B	Radiation resistance
C	Antenna radiation pattern
D	Impedance along transmission lines

50. - E9H02

Which is generally true for low band (160 meter and 80 meter) receiving antennas?

Select	Answer
A	All these choices are correct
B	Atmospheric noise is so high that gain over a dipole is not important
C	They must be erected at least 1/2 wavelength above the ground to attain good directivity
D	Low loss coax transmission line is essential for good performance

Figure E6-1

Figure E7-3