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. - E0A11

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

Select	Answer
A	Ingestion of ozone gas from the cooling system
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	Blood clotting from the intense magnetic field

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

3. - E1B12

What must the control operator of a repeater operating in the 70 cm band do if a radiolocation system experiences interference from that repeater?

Select	Answer
A	Reduce the repeater antenna HAAT (Height Above Average Terrain)
B	File an FAA NOTAM (Notice to Airmen) with the repeater system's ERP, call sign, and six-character grid locator
C	Cease operation or make changes to the repeater to mitigate the interference
D	All these choices are correct

4. - E1C13

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

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

5. - E1D06

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

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

6. - E1E10

What must the administering VEs do after the administration of a successful examination for an amateur operator license?

Select	Answer
A	They must collect and send the documents to the FCC according to instructions
B	They must collect and submit the documents to the coordinating VEC for grading
C	They must collect and send the documents to the NCVEC for grading
D	They must submit the application document to the coordinating VEC according to the coordinating VEC instructions

7. - E1F02

What privileges are authorized in the U.S. to persons holding an amateur service license granted by the government of Canada?

Select	Answer
A	Full privileges, up to and including those of the Amateur Extra Class license, on the 80, 40, 20, 15, and 10 meter bands
B	None, they must obtain a U.S. license
C	All privileges of the Amateur Extra Class license
D	The operating terms and conditions of the Canadian amateur service license, not to exceed U.S. Amateur Extra Class license privileges

8. - E2A09

What do the terms L band and S band specify regarding satellite communications?

Select	Answer
A	FM and Digital Store-and-Forward systems
B	Which sideband to use
C	The 2 meter and 70 centimeter bands
D	The 23 centimeter and 13 centimeter bands

9. - E2B07

What is the name of the signal component that carries color information in NTSC video?

Select	Answer
A	Luminance
B	Hue
C	Spectral intensity
D	Chroma

10. - E2C03

From which of the following bands is amateur radio contesting generally excluded?

Select	Answer
A	2 meters
B	6 meters
C	30 meters
D	33 centimeters

11. - E2D11

Which of the following data are used by the APRS network to communicate station location?

Select	Answer
A	Time and frequency
B	Latitude and longitude
C	Radio direction finding spectrum analysis
D	Polar coordinates

12. - E2E04

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

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

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 F1 layer
C	The E layer
D	The D layer

14. - E3B04

What is meant by the terms "extraordinary" and "ordinary" waves?

Select	Answer
A	Independent waves created in the ionosphere that are elliptically polarized
B	Extraordinary waves describe rare long-skip propagation compared to ordinary waves, which travel shorter distances
C	Long-path and short-path waves
D	Refracted rays and reflected waves

15. - E3C13

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

Select	Answer
A	Elliptical
B	Horizontal
C	Circular
D	Vertical

16. - E4A05

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

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

17. - E4B10

Which of the following methods measures intermodulation distortion in an SSB transmitter?

Select	Answer
A	Modulate the transmitter using two RF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
B	Modulate the transmitter using two RF signals having harmonically related frequencies and observe the RF output with a logic analyzer
C	Modulate the transmitter using two AF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
D	Modulate the transmitter using two AF signals having harmonically related frequencies and observe the RF output with a peak reading wattmeter

18. - E4C08

An SDR receiver is overloaded when input signals exceed what level?

Select	Answer
A	The maximum count value of the analog-to-digital converter
B	One-half the maximum sampling buffer size
C	The reference voltage of the analog-to-digital converter
D	One-half the maximum sample rate

19. - E4D07

Which of the following reduces the likelihood of receiver desensitization?

Select	Answer
A	Decrease the RF bandwidth of the receiver
B	Switch from fast AGC to slow AGC
C	Raise the receiver IF frequency
D	Increase the receiver front end gain

20. - E4E04

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

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

21. - E5A04

What is the magnitude of the impedance of a parallel RLC circuit at resonance?

Select	Answer
A	High compared to the circuit resistance
B	Approximately equal to circuit resistance
C	Low compared to the circuit resistance
D	Approximately equal to inductive reactance

22. - E5B09

What is the relationship between the AC current through a capacitor and the voltage across a capacitor?

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

23. - E5C11

Which point in Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and an 18-microhenry inductor at 3.505 MHz?

Select	Answer
A	Point 3
B	Point 1
C	Point 7
D	Point 8

24. - E5D07

How many watts are consumed in a circuit having a power factor of 0.71 if the apparent power is 500VA?

Select	Answer
A	1.42 mW
B	355 W
C	252 W
D	704 W

25. - E6A09

What is a depletion-mode FET?

Select	Answer
A	Any FET for which holes are the majority carriers
B	Any FET without a channel
C	An FET that exhibits a current flow between source and drain when no gate voltage is applied
D	An FET that has no current flow between source and drain when no gate voltage is applied

26. - E6B11

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

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

27. - E6C06

Why do CMOS digital integrated circuits have high immunity to noise on the input signal or power supply?

Select	Answer
A	The input switching threshold is about one-half the power supply voltage
B	The input switching threshold is about two times the power supply voltage
C	Bandwidth is very limited
D	Large bypass capacitance is inherent

28. - E6D10

What is a primary advantage of using a toroidal core instead of a solenoidal core in an inductor?

Select	Answer
A	Toroidal cores make it easier to couple the magnetic energy into other components
B	Toroidal cores have lower Q characteristics
C	Toroidal cores confine most of the magnetic field within the core material
D	Toroidal cores exhibit greater hysteresis

29. - E6E07

What type of transmission line is used for connections to MMICs?

Select	Answer
A	Circular waveguide
B	Microstrip
C	Miniature coax
D	Parallel wire

30. - E6F04

What is the photovoltaic effect?

Select	Answer
A	The conversion of light to electrical energy
B	The conversion of electrical energy to mechanical energy
C	The conversion of voltage to current when exposed to light
D	The tendency of a battery to discharge when exposed to light

31. - E7A09

What logical operation is performed by an exclusive NOR gate?

Select	Answer
A	It produces logic 1 at its output only if all inputs are logic 1
B	It produces logic 0 at its output only if all inputs are logic 0
C	It produces logic 0 at its output if only one input is logic 1
D	It produces logic 1 at its output if only one input is logic 1

32. - E7B14

Why are switching amplifiers more efficient than linear amplifiers?

Select	Answer
A	Switching amplifiers operate at higher voltages
B	The power transistor is at saturation or cutoff most of the time
C	Linear amplifiers have high gain resulting in higher harmonic content
D	Switching amplifiers use push-pull circuits

33. - E7C04

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

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

34. - E7D07

What is the purpose of C2 in the circuit shown in Figure E7-2?

Select	Answer
A	It bypasses rectifier output ripple around D1
B	To self-resonate at the hum frequency
C	To provide fixed DC bias for Q1
D	It is a brute force filter for the output

35. - E7E05

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

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

36. - E7F11

What sets the minimum detectable signal level for a direct-sampling SDR receiver in the absence of atmospheric or thermal noise?

Select	Answer
A	Data storage transfer rate
B	Missing codes and jitter
C	Sample clock phase noise
D	Reference voltage level and sample width in bits

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	76
B	1
C	0.03
D	38

38. - E7H10

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

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

39. - E8A07

What determines the PEP-to-average power ratio of a single-sideband phone signal?

Select	Answer
A	The degree of carrier suppression
B	Speech characteristics
C	The frequency of the modulating signal
D	Amplifier gain

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

41. - E8C02

What is the definition of symbol rate in a digital transmission?

Select	Answer
A	The duration of each bit in a message sent over the air
B	The rate at which the waveform changes to convey information
C	The number of characters carried per second by the station-to-station link
D	The number of control characters in a message packet

42. - E8D09

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

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

43. - E9A03

What is the radiation resistance of an antenna?

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

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. - E9C04

What happens to the radiation pattern of an unterminated long wire antenna as the wire length is increased?

Select	Answer
A	The front-to-back ratio decreases
B	The vertical angle increases
C	The lobes become more perpendicular to the wire
D	The lobes align more in the direction of the wire

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

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 stub match
B	The delta match
C	The gamma match
D	The epsilon match

48. - E9F10

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

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

49. - E9G11

How are the wavelength scales on a Smith chart calibrated?

Select	Answer
A	In fractions of transmission line electrical frequency
B	In fractions of antenna electrical frequency
C	In fractions of transmission line electrical wavelength
D	In fractions of antenna electrical wavelength

50. - E9H06

What is the triangulation method of direction finding?

Select	Answer
A	A fixed receiving station uses three different antennas to plot the location of the signal source
B	A fixed receiving station plots three headings to the signal source
C	The geometric angles of sky waves from the source are used to determine its position
D	Antenna headings from several different receiving locations are used to locate the signal source

Figure E5-1

Figure E7-2

Figure E7-3

Figure E9-1