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

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

1. - E0A07

How may dangerous levels of carbon monoxide from an emergency generator be detected?

Select	Answer
A	Only with a carbon monoxide detector
B	Any ordinary smoke detector can be used
C	By the odor
D	By the yellowish appearance of the gas

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

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. - E1C13

What notifications must be given before transmitting on the 630 meter or 2200 meter bands?

Select	Answer
A	Operators must inform the Utilities Technology Council (UTC) of their call sign and coordinates of the station
B	An environmental impact statement must be filed with the Department of the Interior
C	A special endorsement must be requested from the FCC
D	Operators must inform the FAA of their intent to operate, giving their call sign and distance to the nearest runway

5. - E1D06

What is the maximum permitted transmitter output power when operating a model craft by telecommand?

Select	Answer
A	2 watts
B	1 watt
C	5 watts
D	100 watts

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

7. - E1F01

On what frequencies are spread spectrum transmissions permitted?

Select	Answer
A	Only on amateur frequencies above 420 MHz
B	Only on amateur frequencies above 144 MHz
C	Only on amateur frequencies above 50 MHz
D	Only on amateur frequencies above 222 MHz

8. - E2A06

What are Keplerian elements?

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

9. - E2B09

What hardware, other than a receiver with SSB capability and a suitable computer, is needed to decode SSTV using Digital Radio Mondiale (DRM)?

Select	Answer
A	A special front end limiter
B	No other hardware is needed
C	A special IF converter
D	A special notch filter to remove synchronization pulses

10. - E2C09

What type of equipment is commonly used to implement an amateur radio mesh network?

Select	Answer
A	A wireless router running custom firmware
B	A 2 meter VHF transceiver with a 1200 baud modem
C	A 440 MHz transceiver with a 9600 baud modem
D	An optical cable connection between the USB ports of 2 separate computers

11. - E2D02

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

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

12. - E2E04

What is indicated when one of the ellipses in an FSK crossed-ellipse display suddenly disappears?

Select	Answer
A	Selective fading has occurred
B	The mark and space signal have been inverted
C	The receiver has drifted 5 kHz from the desired receive frequency
D	One of the signal filters is saturated

13. - E3A06

What might help to restore contact when DX signals become too weak to copy across an entire HF band a few hours after sunset?

Select	Answer
A	Switch to a higher frequency HF band
B	Wait 90 minutes or so for the signal degradation to pass
C	Wait 24 hours before attempting another communication on the band
D	Switch to a lower frequency HF band

14. - E3B02

What is the approximate maximum range for signals using transequatorial propagation?

Select	Answer
A	7500 miles
B	1000 miles
C	2500 miles
D	5000 miles

15. - E3C13

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

Select	Answer
A	Elliptical
B	Circular
C	Vertical
D	Horizontal

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

17. - E4B04

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

Select	Answer
A	S22
B	S11
C	S12
D	S21

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 limits the receiver's ability to receive strong signals
C	It can affect the receiver's frequency calibration
D	It can combine with strong signals on nearby frequencies to generate interference

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

20. - E4E04

How can conducted and radiated noise caused by an automobile alternator be suppressed?

Select	Answer
A	By installing a high-pass filter in series with the radio's power lead and a low-pass filter in parallel with the field lead
B	By installing a noise suppression resistor and a blocking capacitor in both leads
C	By installing filter capacitors in series with the DC power lead and a blocking capacitor in the field lead
D	By connecting the radio's power leads directly to the battery and by installing coaxial capacitors in line with the alternator leads

21. - E5A13

What is an effect of increasing Q in a series resonant circuit?

Select	Answer
A	Parasitic effects are minimized
B	Phase shift can become uncontrolled
C	Internal voltages increase
D	Fewer components are needed for the same performance

22. - E5B07

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 500 ohms, R is 1 kilohm, and XL is 250 ohms?

Select	Answer
A	68.2 degrees with the voltage lagging the current
B	14.0 degrees with the voltage lagging the current
C	68.2 degrees with the voltage leading the current
D	14.0 degrees with the voltage leading the current

23. - E5C03

Which of the following represents an inductive reactance in polar coordinates?

Select	Answer
A	A positive magnitude
B	A negative magnitude
C	A positive phase angle
D	A negative phase angle

24. - E5D15

What is the power factor of an RL circuit having a 45-degree phase angle between the voltage and the current?

Select	Answer
A	1.0
B	0.866
C	0.5
D	0.707

25. - E6A02

Which of the following semiconductor materials contains excess free electrons?

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

26. - E6B09

What is a common use for point-contact diodes?

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

27. - E6C07

What best describes a pull-up or pull-down resistor?

Select	Answer
A	A resistor connected to an op-amp output that prevents signals from exceeding the power supply voltage
B	A resistor in a keying circuit used to reduce key clicks
C	A resistor connected to the positive or negative supply line used to establish a voltage when an input or output is an open circuit
D	A resistor that ensures that an oscillator frequency does not drift

28. - E6D03

Which of the following is an aspect of the piezoelectric effect?

Select	Answer
A	Increased conductivity in the presence of light
B	Mechanical deformation of material by the application of a magnetic field
C	Mechanical deformation of material by the application of a voltage
D	Generation of electrical energy in the presence of light

29. - E6E05

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

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

30. - E6F07

What is a solid-state relay?

Select	Answer
A	A mechanical relay that latches in the on or off state each time it is pulsed
B	A semiconductor passive delay line
C	A device that uses semiconductors to implement the functions of an electromechanical relay
D	A relay using transistors to drive the relay coil

31. - E7A07

What logical operation does a NAND gate perform?

Select	Answer
A	It produces logic 0 at its output if some but not all inputs are logic 1
B	It produces logic 0 at its output only when 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. - E7B03

Which of the following components form the output of a class D amplifier circuit?

Select	Answer
A	A high-pass filter to compensate for low gain at low frequencies
B	A temperature compensating load resistor to improve linearity
C	A matched load resistor to prevent damage by switching transients
D	A low-pass filter to remove switching signal components

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

34. - E7D09

What is the main reason to use a charge controller with a solar power system?

Select	Answer
A	Prevention of battery undercharge
B	Matching of day and night charge rates
C	Control of electrolyte levels during battery discharge
D	Prevention of battery damage due to overcharge

35. - E7E01

Which of the following can be used to generate FM phone emissions?

Select	Answer
A	A reactance modulator on the final amplifier
B	A balanced modulator on the audio amplifier
C	A reactance modulator on the oscillator
D	A balanced modulator on the oscillator

36. - E7F06

What is the minimum number of bits required for an analog-to-digital converter to sample a signal with a range of 1 volt at a resolution of 1 millivolt?

Select	Answer
A	4 bits
B	6 bits
C	8 bits
D	10 bits

37. - E7G03

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

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

38. - E7H06

Which of the following oscillator circuits are commonly used in VFOs?

Select	Answer
A	Colpitts and Hartley
B	Negative feedback and balanced feedback
C	Pierce and Zener
D	Armstrong and deForest

39. - E8A11

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

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

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 audio modulating frequency to the center carrier frequency
C	The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency
D	The ratio of the carrier center frequency to the audio modulating frequency

41. - E8C12

What factors affect the bandwidth of a transmitted CW signal?

Select	Answer
A	Keying speed and shape factor (rise and fall time)
B	IF bandwidth and Q
C	Modulation index and output power
D	All these choices are correct

42. - E8D04

What is the primary effect of extremely short rise or fall time on a CW signal?

Select	Answer
A	Limits data speed
B	More difficult to copy
C	The generation of RF harmonics
D	The generation of key clicks

43. - E9A10

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

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

44. - E9B01

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

Select	Answer
A	75 degrees
B	30 degrees
C	25 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	Omni-directional
B	Cardioid
C	A figure-8 broadside to the axis of the array
D	A figure-8 end-fire along the axis of the array

46. - E9D01

How much does the gain of an ideal parabolic dish antenna change when the operating frequency is doubled?

Select	Answer
A	4 dB
B	3 dB
C	6 dB
D	2 dB

47. - E9E06

Which of these feed line impedances would be suitable for constructing a quarter-wave Q-section for matching a 100-ohm loop to 50-ohm feed line?

Select	Answer
A	75 ohms
B	62 ohms
C	450 ohms
D	50 ohms

48. - E9F11

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

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

49. - E9G07

On the Smith chart shown in Figure E9-3, what is the only straight line shown?

Select	Answer
A	The reactance axis
B	The voltage axis
C	The current axis
D	The resistance axis

50. - E9H05

What is the main drawback of a small wire-loop antenna for direction finding?

Select	Answer
A	It is practical for use only on VHF and higher bands
B	All these choices are correct
C	It has no clearly defined null
D	It has a bidirectional pattern

Figure E9-1

Figure E9-3