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

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1. - E0A11

Which of the following injuries can result from using high-power UHF or microwave transmitters?

Select	Answer
A	Blood clotting from the intense magnetic field
B	Localized heating of the body from RF exposure in excess of the MPE limits
C	Hearing loss caused by high voltage corona discharge
D	Ingestion of ozone gas from the cooling system

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

3. - E1B05

What is the National Radio Quiet Zone?

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

4. - E1C01

What is the maximum bandwidth for a data emission on 60 meters?

Select	Answer
A	2.8 kHz
B	60 Hz
C	170 Hz
D	1.5 kHz

5. - E1D03

What is a space telecommand station?

Select	Answer
A	An amateur station that transmits communications to initiate, modify or terminate functions of a space station
B	An amateur station that receives telemetry from a satellite or balloon more than 50 kilometers above the surface of the Earth
C	An amateur station located on the surface of the Earth for communication with other Earth stations by means of Earth satellites
D	An amateur station located in a satellite or a balloon more than 50 kilometers above the surface of the Earth

6. - E1E08

To which of the following examinees may a VE not administer an examination?

Select	Answer
A	All these choices are correct
B	Relatives of the VE as listed in the FCC rules
C	Friends of the VE
D	Employees of the VE

7. - 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

8. - E2A05

What do the letters in a satellite's mode designator specify?

Select	Answer
A	The polarization of uplink and downlink signals
B	The uplink and downlink frequency ranges
C	The location of the ground control station
D	Power limits for uplink and downlink transmissions

9. - E2B06

What is vestigial sideband modulation?

Select	Answer
A	Amplitude modulation in which one complete sideband and a portion of the other are transmitted
B	Narrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier
C	A type of modulation in which one sideband is inverted
D	Spread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation

10. - E2C02

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

Select	Answer
A	An automatic method for rapidly zero beating or tuning to a station's frequency before calling that station
B	The often-prohibited practice of posting one's own call sign and frequency on a spotting network
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. - E2D02

Which of the following is a good technique for making meteor scatter contacts?

Select	Answer
A	Short transmissions with rapidly repeated call signs and signal reports
B	All these choices are correct
C	Use of special digital modes
D	15-second timed transmission sequences with stations alternating based on location

12. - E2E02

What do the letters FEC mean as they relate to digital operation?

Select	Answer
A	First Error Correction
B	Forward Error Correction
C	Final Error Correction
D	Fatal Error Correction

13. - E3A02

What characterizes libration fading of an EME signal?

Select	Answer
A	The returning echo is several hertz lower in frequency than the transmitted signal
B	A gradual loss of signal as the sun rises
C	A fluttery irregular fading
D	A slow change in the pitch of the CW signal

14. - E3B05

Which amateur bands typically support long-path propagation?

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

15. - E3C02

What is indicated by a rising A or K index?

Select	Answer
A	Higher levels of solar UV radiation
B	Increasing disruption of the geomagnetic field
C	Decreasing disruption of the geomagnetic field
D	An increase in the critical frequency

16. - E4A04

How is the compensation of an oscilloscope probe typically adjusted?

Select	Answer
A	A square wave is displayed and the probe is adjusted until the horizontal portions of the displayed wave are as nearly flat as possible
B	A high frequency sine wave is displayed and the probe is adjusted for maximum amplitude
C	A DC voltage standard is displayed and the probe is adjusted until the displayed voltage is accurate
D	A frequency standard is displayed and the probe is adjusted until the deflection time is accurate

17. - E4B04

Which S parameter represents input port return loss or reflection coefficient (equivalent to VSWR)?

Select	Answer
A	S22
B	S11
C	S21
D	S12

18. - E4C05

What does a receiver noise floor of -174 dBm represent?

Select	Answer
A	The galactic noise contribution to minimum detectable signal
B	The minimum detectable signal as a function of receive frequency
C	The noise figure of a 1 Hz bandwidth receiver
D	The theoretical noise in a 1 Hz bandwidth at the input of a perfect receiver at room temperature

19. - E4D05

What transmitter frequencies would cause an intermodulation-product signal in a receiver tuned to 146.70 MHz when a nearby station transmits on 146.52 MHz?

Select	Answer
A	146.10 MHz and 147.30 MHz
B	146.88 MHz and 146.34 MHz
C	146.34 MHz and 146.61 MHz
D	173.35 MHz and 139.40 MHz

20. - E4E09

What undesirable effect can occur when using an IF noise blanker?

Select	Answer
A	Nearby signals may appear to be excessively wide even if they meet emission standards
B	Received audio in the speech range might have an echo effect
C	FM signals can no longer be demodulated
D	The audio frequency bandwidth of the received signal might be compressed

21. - E5A02

What is resonance in an LC or RLC circuit?

Select	Answer
A	The lowest frequency that will pass current
B	The highest frequency that will pass current
C	The frequency at which the capacitive reactance equals the inductive reactance
D	The frequency at which the reactive impedance equals the resistive impedance

22. - E5B10

What is the relationship between the AC current through an inductor and the voltage across an inductor?

Select	Answer
A	Current leads voltage by 90 degrees
B	Voltage and current are 180 degrees out of phase
C	Voltage leads current by 90 degrees
D	Voltage and current are in phase

23. - E5C01

Which of the following represents capacitive reactance in rectangular notation?

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

24. - E5D03

What is microstrip?

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

25. - E6A12

Why do many MOSFET devices have internally connected Zener diodes on the gates?

Select	Answer
A	To keep the gate voltage within specifications and prevent the device from overheating
B	To provide a voltage reference for the correct amount of reverse-bias gate voltage
C	To reduce the chance of static damage to the gate
D	To protect the substrate from excessive voltages

26. - E6B02

What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

Select	Answer
A	More constant reverse avalanche voltage
B	Much higher reverse voltage breakdown
C	Less forward voltage drop
D	Longer carrier retention time

27. - E6C11

In Figure E6-3, what is the schematic symbol for the NOT operation (inverter)?

Select	Answer
A	5
B	6
C	4
D	2

28. - E6D13

What is the primary cause of inductor self-resonance?

Select	Answer
A	The skin effect
B	Inductive kickback
C	Non-linear core hysteresis
D	Inter-turn capacitance

29. - E6E12

Why are DIP through-hole package ICs not typically used at UHF and higher frequencies?

Select	Answer
A	Epoxy coating is conductive above 300 MHz
B	Excessive lead length
C	Unsuitable for combining analog and digital signals
D	Too many pins

30. - E6F01

What absorbs the energy from light falling on a photovoltaic cell?

Select	Answer
A	Photons
B	Electrons
C	Holes
D	Protons

31. - E7A07

What logical operation does a NAND gate perform?

Select	Answer
A	It produces logic 0 at its output only when all inputs are logic 1
B	It produces logic 0 at its output if some but not all inputs are logic 1
C	It produces logic 0 at its output only when all inputs are logic 0
D	It produces logic 1 at its output only when all inputs are logic 1

32. - E7B05

What can be done to prevent unwanted oscillations in an RF power amplifier?

Select	Answer
A	Install parasitic suppressors and/or neutralize the stage
B	Use a phase inverter in the output filter
C	Tune the stage for maximum SWR
D	Tune both the input and output for maximum power

33. - E7C04

How does an impedance-matching circuit transform a complex impedance to a resistive impedance?

Select	Answer
A	It introduces transconductance to cancel the reactive part of impedance
B	Reactive currents are dissipated in matched resistances
C	It introduces negative resistance to cancel the resistive part of impedance
D	It cancels the reactive part of the impedance and changes the resistive part to a desired value

34. - E7D08

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

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

35. - E7E02

What is the function of a reactance modulator?

Select	Answer
A	To produce PM signals by using an electrically variable resistance
B	To produce PM or FM signals by using an electrically variable inductance or capacitance
C	To produce AM signals by using an electrically variable resistance
D	To produce AM signals by using an electrically variable inductance or capacitance

36. - E7F12

Which of the following is an advantage of a Finite Impulse Response (FIR) filter vs an Infinite Impulse Response (IIR) digital filter?

Select	Answer
A	FIR filters are easier to implement for a given set of passband rolloff requirements
B	FIR filters can respond faster to impulses
C	FIR filters can delay all frequency components of the signal by the same amount
D	All these choices are correct

37. - E7G06

What is the gain-bandwidth of an operational amplifier?

Select	Answer
A	The gain of the amplifier at a filter's cutoff frequency
B	The frequency at which the amplifier's offset voltage is zero
C	The maximum frequency for a filter circuit using that type of amplifier
D	The frequency at which the open-loop gain of the amplifier equals one

38. - E7H08

Which of the following components can be used to reduce thermal drift in crystal oscillators?

Select	Answer
A	Toroidal inductors
B	Non-inductive resistors
C	NP0 capacitors
D	Wirewound resistors

39. - E8A04

What is "dither" with respect to analog-to-digital converters?

Select	Answer
A	A small amount of noise added to the input signal to allow more precise representation of a signal over time
B	An error caused by irregular quantization step size
C	An abnormal condition where the converter cannot settle on a value to represent the signal
D	A method of decimation by randomly skipping samples

40. - E8B09

What is deviation ratio?

Select	Answer
A	The ratio of the highest audio modulating frequency to the average audio modulating frequency
B	The ratio of the carrier center frequency to the audio modulating frequency
C	The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency
D	The ratio of the audio modulating frequency to the center carrier frequency

41. - E8C10

How may data rate be increased without increasing bandwidth?

Select	Answer
A	Increasing analog-to-digital conversion resolution
B	Using a more efficient digital code
C	It is impossible
D	Using forward error correction

42. - E8D11

What is one advantage of using ASCII code for data communications?

Select	Answer
A	It uses one character as a shift code to send numeric and special characters
B	It includes built-in error correction features
C	It is possible to transmit both upper and lower case text
D	It contains fewer information bits per character than any other code

43. - E9A10

Which of the following improves the efficiency of a ground-mounted quarter-wave vertical antenna?

Select	Answer
A	Isolating the coax shield from ground
B	Shortening the radiating element
C	All these choices are correct
D	Installing a radial system

44. - E9B07

How does the total amount of radiation emitted by a directional gain antenna compare with the total amount of radiation emitted from a theoretical isotropic antenna, assuming each is driven by the same amount of power?

Select	Answer
A	The radiation from the isotropic antenna is 2.15 dB stronger than that from the directional antenna
B	They are the same
C	The total amount of radiation from the directional antenna is stronger by its front-to-back ratio
D	The total amount of radiation from the directional antenna is increased by the gain of the antenna

45. - E9C12

Which of the following describes an Extended Double Zepp antenna?

Select	Answer
A	A portable antenna erected using two push support poles
B	An end-fed folded dipole antenna
C	A wideband vertical antenna constructed from precisely tapered aluminum tubing
D	A center-fed 1.25-wavelength antenna (two 5/8-wave elements in phase)

46. - E9D12

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

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

47. - E9E02

What is the name of an antenna matching system that matches an unbalanced feed line to an antenna by feeding the driven element both at the center of the element and at a fraction of a wavelength to one side of center?

Select	Answer
A	The epsilon match
B	The stub match
C	The delta match
D	The gamma match

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	8.3 meters
B	10.4 meters
C	5.2 meters
D	6.9 meters

49. - E9G09

What third family of circles is often added to a Smith chart during the process of solving problems?

Select	Answer
A	Radiation-pattern circles
B	Coaxial-length circles
C	Standing wave ratio circles
D	Antenna-length circles

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

Figure E6-3

Figure E7-2