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. - E0A08

What does SAR measure?

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

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

3. - E1B04

What must be done before placing an amateur station within an officially designated wilderness area or wildlife preserve, or an area listed in the National Register of Historic Places?

Select	Answer
A	A proposal must be submitted to the National Park Service
B	A letter of intent must be filed with the Environmental Protection Agency
C	An Environmental Assessment must be submitted to the FCC
D	A form FSD-15 must be submitted to the Department of the Interior

4. - E1C10

What is the permitted mean power of any spurious emission relative to the mean power of the fundamental emission from a station transmitter or external RF amplifier installed after January 1, 2003 and transmitting on a frequency below 30 MHz?

Select	Answer
A	At least 73 dB below
B	At least 63 dB below
C	At least 43 dB below
D	At least 53 dB below

5. - E1D08

Which VHF amateur bands have frequencies authorized for space stations?

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

6. - E1E09

What may be the penalty for a VE who fraudulently administers or certifies an examination?

Select	Answer
A	A fine of up to $1000 per occurrence
B	A sentence of up to one year in prison
C	Revocation of the VE's amateur station license grant and the suspension of the VE's amateur operator license grant
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 provide temporary operation while awaiting normal licensing
B	To provide for experimental amateur communications
C	To allow regular operation on Land Mobile channels
D	To provide additional spectrum for personal use

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 interfering with terrestrial QSOs
C	To avoid reducing the downlink power to all other users
D	To prevent the satellite from emitting out-of-band signals

9. - E2B06

What is vestigial sideband modulation?

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

10. - E2C11

How should you generally identify your station when attempting to contact a DX station during a contest or in a pileup?

Select	Answer
A	Send the call sign of the DX station three times, the words this is,then your call sign three times
B	Send only the last two letters of your call sign until you make contact
C	Send your full call sign and grid square
D	Send your full call sign once or twice

11. - E2D03

Which of the following digital modes is especially useful for EME communications?

Select	Answer
A	JT65
B	MSK144
C	PACTOR III
D	Olivia

12. - E2E05

Which of these digital modes does not support keyboard-to-keyboard operation?

Select	Answer
A	MFSK
B	PACTOR
C	PSK31
D	RTTY

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

14. - E3B05

Which amateur bands typically support long-path propagation?

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

15. - E3C02

What is indicated by a rising A or K index?

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

16. - E4A05

What is the purpose of the prescaler function on a frequency counter?

Select	Answer
A	It amplifies low-level signals for more accurate counting
B	It multiplies a higher frequency signal so a low-frequency counter can display the operating frequency
C	It prevents oscillation in a low-frequency counter circuit
D	It divides a higher frequency signal so a low-frequency counter can display the input frequency

17. - E4B02

What is the significance of voltmeter sensitivity expressed in ohms per volt?

Select	Answer
A	When used as an ammeter, the full scale reading in amps divided by ohms per volt rating will determine the size of shunt needed
B	The full scale reading of the voltmeter multiplied by its ohms per volt rating will indicate the input impedance of the voltmeter
C	When used as a galvanometer, the reading in volts multiplied by the ohms per volt rating will determine the power drawn by the device under test
D	When used as an ohmmeter, the reading in ohms divided by the ohms per volt rating will determine the voltage applied to the circuit

18. - E4C10

What is an advantage of having a variety of receiver IF bandwidths from which to select?

Select	Answer
A	Multiple frequencies can be received simultaneously if desired
B	Receive bandwidth can be set to match the modulation bandwidth, maximizing signal-to-noise ratio and minimizing interference
C	Receiver power consumption can be reduced when wider bandwidth is not required
D	The noise figure of the RF amplifier can be adjusted to match the modulation type, thus increasing receiver sensitivity

19. - E4D06

What is the term for spurious signals generated by the combination of two or more signals in a non-linear device or circuit?

Select	Answer
A	Intermodulation
B	Adjacent channel interference
C	Amplifier desensitization
D	Neutralization

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	The audio frequency bandwidth of the received signal might be compressed
C	Received audio in the speech range might have an echo effect
D	FM signals can no longer be demodulated

21. - E5A05

What is the result of increasing the Q of an impedance-matching circuit?

Select	Answer
A	Matching bandwidth is increased
B	Matching range is increased
C	It has no effect on impedance matching
D	Matching bandwidth is decreased

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

23. - 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	Faraday grid
B	Polar coordinates
C	Elliptical coordinates
D	Maidenhead grid

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

25. - E6A05

How does DC input impedance at the gate of a field-effect transistor compare with the DC input impedance of a bipolar transistor?

Select	Answer
A	An FET has higher input impedance
B	They are both high impedance
C	An FET has lower input impedance
D	They are both low impedance

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

27. - E6C09

What is a Programmable Logic Device (PLD)?

Select	Answer
A	A logic circuit that can be modified during use
B	A programmable collection of logic gates and circuits in a single integrated circuit
C	A type of transistor whose gain can be changed by digital logic circuits
D	Programmable equipment used for testing digital logic integrated circuits

28. - E6D04

Which materials are commonly used as a core in an inductor?

Select	Answer
A	Polystyrene and polyethylene
B	Teflon and Delrin
C	Ferrite and brass
D	Cobalt and aluminum

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	Plate current that is controlled by a control grid
C	Nearly infinite gain, very high input impedance, and very low output impedance
D	Controlled gain, low noise figure, and constant input and output impedance over the specified frequency range

30. - E6F07

What is a solid-state relay?

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

31. - E7A11

What type of logic defines "1" as a high voltage?

Select	Answer
A	Positive Logic
B	Reverse Logic
C	Negative logic
D	Assertive Logic

32. - E7B07

Which of the following is a likely result when a Class C amplifier is used to amplify a single-sideband phone signal?

Select	Answer
A	Signal inversion
B	Increased overall intelligibility
C	Signal distortion and excessive bandwidth
D	Reduced intermodulation products

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

34. - E7D01

How does a linear electronic voltage regulator work?

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

35. - E7E11

Which type of detector circuit is used for demodulating SSB signals?

Select	Answer
A	Phase detector
B	Phase comparator
C	Product detector
D	Discriminator

36. - E7F09

Why is an anti-aliasing digital filter required in a digital decimator?

Select	Answer
A	It removes high-frequency signal components that would otherwise be reproduced as lower frequency components
B	It peaks the response of the decimator, improving bandwidth
C	It removes low-frequency signal components to eliminate the need for DC restoration
D	It notches out the sampling frequency to avoid sampling errors

37. - E7G03

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

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

38. - E7H13

Which of the following is a technique for providing highly accurate and stable oscillators needed for microwave transmission and reception?

Select	Answer
A	Use a rubidium stabilized reference oscillator
B	Use a temperature-controlled high Q dielectric resonator
C	All these choices are correct
D	Use a GPS signal reference

39. - E8A05

What of the following instruments would be the most accurate for measuring the RMS voltage of a complex waveform?

Select	Answer
A	A D'Arsonval meter
B	A grid dip meter
C	An absorption wave meter
D	A true-RMS calculating meter

40. - E8B06

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz when the maximum modulation frequency is 3.5 kHz?

Select	Answer
A	0.214
B	2.14
C	0.47
D	47

41. - E8C03

Why should phase-shifting of a PSK signal be done at the zero crossing of the RF signal?

Select	Answer
A	To simplify modulation
B	To minimize bandwidth
C	To improve carrier suppression
D	All these choices are correct

42. - E8D08

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

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

43. - E9A11

Which of the following factors determines ground losses for a ground-mounted vertical antenna operating in the 3 MHz to 30 MHz range?

Select	Answer
A	The standing wave ratio
B	Soil conductivity
C	Distance from the transmitter
D	Take-off angle

44. - E9B01

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

Select	Answer
A	25 degrees
B	30 degrees
C	50 degrees
D	75 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	Cardioid
B	A figure-8 end-fire along the axis of the array
C	A figure-8 broadside to the axis of the array
D	Omni-directional

46. - E9D10

What happens to feed-point impedance at the base of a fixed length HF mobile antenna when operated below its resonant frequency?

Select	Answer
A	The radiation resistance increases and the capacitive reactance increases
B	The radiation resistance decreases and the capacitive reactance increases
C	The radiation resistance decreases and the capacitive reactance decreases
D	The radiation resistance increases and the capacitive reactance decreases

47. - E9E03

What is the name of the matching system that uses a section of transmission line connected in parallel with the feed line at or near the feed point?

Select	Answer
A	The gamma match
B	The delta match
C	The stub match
D	The omega 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	10.4 meters
B	5.2 meters
C	8.3 meters
D	6.9 meters

49. - E9G03

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

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

50. - E9H03

What is Receiving Directivity Factor (RDF)?

Select	Answer
A	Relative directivity compared to a dipole
B	Relative directivity compared to isotropic
C	Forward gain compared to average gain over the entire hemisphere
D	Forward gain compared to the gain in the reverse direction

Figure E9-1