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

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1. - E0A06

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

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

2. - E1A02

When using a transceiver that displays the carrier frequency of phone signals, which of the following displayed frequencies represents the lowest frequency at which a properly adjusted LSB emission will be totally within the band?

Select	Answer
A	The exact lower band edge
B	3 kHz above the lower band edge
C	300 Hz above the lower band edge
D	1 kHz above the lower band edge

3. - E1B09

Which amateur stations may be operated under RACES rules?

Select	Answer
A	Only those club stations licensed to Amateur Extra Class operators
B	Any FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)
C	Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served
D	Any FCC-licensed amateur station except a Technician Class

4. - E1C07

At what level below a signal's mean power level is its bandwidth determined according to FCC rules?

Select	Answer
A	3 dB
B	23 dB
C	26 dB
D	6 dB

5. - E1D08

Which VHF amateur bands have frequencies authorized for space stations?

Select	Answer
A	6 meters, 2 meters, and 1.25 meters
B	2 meters
C	6 meters and 2 meters
D	2 meters and 1.25 meters

6. - E1E11

What must the VE team do if an examinee scores a passing grade on all examination elements needed for an upgrade or new license?

Select	Answer
A	Three VEs must certify that the examinee is qualified for the license grant and that they have complied with the administering VE requirements
B	Photocopy all examination documents and forward them to the FCC for processing
C	Issue the examinee the new or upgrade license
D	All these choices are correct

7. - E1F06

Under what circumstances might the FCC issue a Special Temporary Authority (STA) to an amateur station?

Select	Answer
A	To allow regular operation on Land Mobile channels
B	To provide additional spectrum for personal use
C	To provide for experimental amateur communications
D	To provide temporary operation while awaiting normal licensing

8. - E2A08

Why should effective radiated power to a satellite that uses a linear transponder be limited?

Select	Answer
A	To prevent creating errors in the satellite telemetry
B	To avoid reducing the downlink power to all other users
C	To avoid interfering with terrestrial QSOs
D	To prevent the satellite from emitting out-of-band signals

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	Spread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation
C	A type of modulation in which one sideband is inverted
D	Narrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier

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	The acceptable practice of manually posting the call signs of stations 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. - 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	All these choices are correct
C	APRS stations with General Personnel Scanners can automatically relay the participant numbers and time as they pass the check points
D	An APRS station with an emergency medical technician can automatically transmit medical data to the nearest hospital

12. - E2E09

Which of the following HF digital modes uses variable-length coding for bandwidth efficiency?

Select	Answer
A	MT63
B	RTTY
C	PACTOR
D	PSK31

13. - E3A08

When a meteor strikes the Earth's atmosphere, a cylindrical region of free electrons is formed at what layer of the ionosphere?

Select	Answer
A	The F2 layer
B	The E layer
C	The F1 layer
D	The D layer

14. - E3B07

What happens to linearly polarized radio waves that split into ordinary and extraordinary waves in the ionosphere?

Select	Answer
A	They become depolarized
B	They are bent toward the magnetic poles
C	They become elliptically polarized
D	They become phase locked

15. - E3C01

What does the radio communication term "ray tracing" describe?

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

16. - E4A03

Which of the following test instruments is used to display spurious signals and/or intermodulation distortion products generated by an SSB transmitter?

Select	Answer
A	A spectrum analyzer
B	A logic analyzer
C	A wattmeter
D	A time-domain reflectometer

17. - E4B09

What is indicated if the current reading on an RF ammeter placed in series with the antenna feed line of a transmitter increases as the transmitter is tuned to resonance?

Select	Answer
A	There is possibly a short to ground in the feed line
B	There is an impedance mismatch between the antenna and feed line
C	The transmitter is not properly neutralized
D	There is more power going into the antenna

18. - E4C07

What does the MDS of a receiver represent?

Select	Answer
A	The maximum detectable spectrum
B	The minimum discernible signal
C	The multiplex distortion stability
D	The meter display sensitivity

19. - E4D02

Which of the following describes problems caused by poor dynamic range in a receiver?

Select	Answer
A	Spurious signals caused by cross-modulation and desensitization from strong adjacent signals
B	Oscillator instability and severe audio distortion of all but the strongest received signals
C	Cross-modulation of the desired signal and insufficient audio power to operate the speaker
D	Oscillator instability requiring frequent retuning and loss of ability to recover the opposite sideband

20. - E4E06

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

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

21. - E5A08

What is the phase relationship between the current through and the voltage across a series resonant circuit at resonance?

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

22. - E5B10

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

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

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	Rectangular coordinates
C	Maidenhead grid
D	Faraday grid

24. - E5D02

Why is it important to keep lead lengths short for components used in circuits for VHF and above?

Select	Answer
A	To maintain component lifetime
B	To increase the thermal time constant
C	To avoid unwanted inductive reactance
D	All these choices are correct

25. - E6A10

In Figure E6-1, what is the schematic symbol for an N-channel dual-gate MOSFET?

Select	Answer
A	5
B	6
C	4
D	2

26. - E6B11

What is used to control the attenuation of RF signals by a PIN diode?

Select	Answer
A	Forward DC bias current
B	Reverse voltage larger than the RF signal
C	Capacitance of an RF coupling capacitor
D	A sub-harmonic pump signal

27. - E6C05

What is an advantage of CMOS logic devices over TTL devices?

Select	Answer
A	Lower power consumption
B	Differential output capability
C	Immune to damage from static discharge
D	Lower distortion

28. - E6D02

What is the equivalent circuit of a quartz crystal?

Select	Answer
A	Motional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in parallel
B	Motional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in series
C	Motional capacitance, motional inductance, and loss resistance in series, all in parallel with a shunt capacitor representing electrode and stray capacitance
D	Motional inductance and loss resistance in series, paralleled with motional capacitance and a capacitor representing electrode and stray capacitance

29. - E6E06

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

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

30. - E6F02

What happens to the conductivity of a photoconductive material when light shines on it?

Select	Answer
A	It stays the same
B	It becomes unstable
C	It decreases
D	It increases

31. - E7A10

What is a truth table?

Select	Answer
A	A list of inputs and corresponding outputs for a digital device
B	A table of logic symbols that indicate the logic states of an op-amp
C	A diagram showing logic states when the digital device output is true
D	A table of logic symbols that indicate the high logic states of an op-amp

32. - E7B16

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

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

33. - E7C10

Which of the following filters would be the best choice for use in a 2 meter band repeater duplexer?

Select	Answer
A	A DSP filter
B	A crystal filter
C	A cavity filter
D	An L-C filter

34. - E7D08

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

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

35. - E7E05

What circuit is added to an FM transmitter to boost the higher audio frequencies?

Select	Answer
A	A heterodyne suppressor
B	A pre-emphasis network
C	A de-emphasis network
D	A heterodyne enhancer

36. - E7F02

What kind of digital signal processing audio filter is used to remove unwanted noise from a received SSB signal?

Select	Answer
A	A phase-inverting filter
B	A crystal-lattice filter
C	A Hilbert-transform filter
D	An adaptive filter

37. - E7G04

What is meant by the "op-amp input offset voltage"?

Select	Answer
A	The differential input voltage needed to bring the open loop output voltage to zero
B	The potential between the amplifier input terminals of the op-amp in an open loop condition
C	The difference between the output voltage of the op-amp and the input voltage required in the immediately following stage
D	The output voltage of the op-amp minus its input voltage

38. - E7H05

How is positive feedback supplied in a Pierce oscillator?

Select	Answer
A	Through a tapped coil
B	Through a quartz crystal
C	Through a neutralizing capacitor
D	Through link coupling

39. - E8A11

Which of the following is a measure of the quality of an analog-to-digital converter?

Select	Answer
A	Reciprocal mixing
B	Total harmonic distortion
C	Peak envelope power
D	Power factor

40. - E8B02

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

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

41. - E8C04

What technique minimizes the bandwidth of a PSK31 signal?

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

42. - E8D09

What is considered an acceptable maximum IMD level for an idling PSK signal?

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

43. - E9A04

Which of the following factors affect the feed point impedance of an antenna?

Select	Answer
A	The settings of an antenna tuner at the transmitter
B	Antenna height
C	Transmission line length
D	The input power level

44. - E9B01

In the antenna radiation pattern shown in Figure E9-1, what is the beamwidth?

Select	Answer
A	25 degrees
B	75 degrees
C	30 degrees
D	50 degrees

45. - E9C02

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/4 wavelength apart and fed 90 degrees out of phase?

Select	Answer
A	A figure-8 end-fire along the axis of the array
B	Omni-directional
C	A figure-8 broadside to the axis of the array
D	Cardioid

46. - E9D06

What happens to the SWR bandwidth when one or more loading coils are used to resonate an electrically short antenna?

Select	Answer
A	It is increased
B	It is unchanged if the loading coil is located at the feed point
C	It is decreased
D	It is unchanged if the loading coil is located at a voltage maximum point

47. - E9E07

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

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

48. - E9F06

What is the approximate physical length of an air-insulated, parallel conductor transmission line that is electrically 1/2 wavelength long at 14.10 MHz?

Select	Answer
A	13.3 meters
B	7.0 meters
C	10.6 meters
D	8.5 meters

49. - E9G10

What do the arcs on a Smith chart represent?

Select	Answer
A	Frequency
B	SWR
C	Points with constant resistance
D	Points with constant reactance

50. - E9H01

When constructing a Beverage antenna, which of the following factors should be included in the design to achieve good performance at the desired frequency?

Select	Answer
A	Its overall length must not exceed 1/4 wavelength
B	It should be configured as a four-sided loop
C	It must be mounted more than 1 wavelength above ground
D	It should be one or more wavelengths long

Figure E6-1

Figure E7-2

Figure E9-1