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

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1. - E0A10

What toxic material may be present in some electronic components such as high voltage capacitors and transformers?

Select	Answer
A	Polyethylene
B	Polymorphic silicon
C	Polytetrafluoroethylene
D	Polychlorinated biphenyls

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. - E1B03

Within what distance must an amateur station protect an FCC monitoring facility from harmful interference?

Select	Answer
A	10 miles
B	3 miles
C	1 mile
D	30 miles

4. - E1C14

How long must an operator wait after filing a notification with the Utilities Technology Council (UTC) before operating on the 2200 meter or 630 meter band?

Select	Answer
A	Operators may not operate until a test signal has been transmitted in coordination with the local power company
B	Operators must not operate until approval is received
C	Operators may operate after 30 days, providing they have not been told that their station is within 1 km of PLC systems using those frequencies
D	Operations may commence immediately, and may continue unless interference is reported by the UTC

5. - E1D11

Which amateur stations are eligible to operate as Earth stations?

Select	Answer
A	Only those of General, Advanced or Amateur Extra Class operators
B	Only those of Amateur Extra Class operators
C	Any amateur station whose licensee has filed a pre-space notification with the FCC's International Bureau
D	Any amateur station, subject to the privileges of the class of operator license held by the control operator

6. - E1E01

For which types of out-of-pocket expenses do the Part 97 rules state that VEs and VECs may be reimbursed?

Select	Answer
A	No expenses are authorized for reimbursement
B	Preparing, processing, administering, and coordinating an examination for an amateur radio operator license
C	Providing amateur operator license examination preparation training materials
D	Teaching an amateur operator license examination preparation course

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

8. - E2A05

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

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

9. - E2B01

How many times per second is a new frame transmitted in a fast-scan (NTSC) television system?

Select	Answer
A	60
B	30
C	90
D	120

10. - E2C04

Which of the following frequencies are sometimes used for amateur radio mesh networks?

Select	Answer
A	Cable TV channels 41 through 43
B	Frequencies shared with various unlicensed wireless data services
C	The 60 meter band channel centered on 5373 kHz
D	HF frequencies where digital communications are permitted

11. - E2D01

Which of the following digital modes is designed for meteor scatter communications?

Select	Answer
A	Hellschreiber
B	MSK144
C	WSPR
D	APRS

12. - E2E04

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

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

13. - E3A11

What is a typical range for tropospheric propagation of microwave signals?

Select	Answer
A	1200 miles
B	2500 miles
C	100 miles to 300 miles
D	10 miles to 50 miles

14. - E3B04

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

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

15. - E3C10

What does the 304A solar parameter measure?

Select	Answer
A	The solar emission at 304 GHz, correlated to x-ray flare levels
B	The solar wind velocity at 304 degrees from the solar equator, correlated to solar activity
C	The ratio of x-ray flux to radio flux, correlated to sunspot number
D	UV emissions at 304 angstroms, correlated to the solar flux index

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 divides a higher frequency signal so a low-frequency counter can display the input frequency
C	It prevents oscillation in a low-frequency counter circuit
D	It multiplies a higher frequency signal so a low-frequency counter can display the operating frequency

17. - E4B06

How much power is being absorbed by the load when a directional power meter connected between a transmitter and a terminating load reads 100 watts forward power and 25 watts reflected power?

Select	Answer
A	125 watts
B	100 watts
C	75 watts
D	25 watts

18. - E4C08

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

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

19. - E4D01

What is meant by the blocking dynamic range of a receiver?

Select	Answer
A	The difference in dB between the noise floor and the level of an incoming signal that will cause 1 dB of gain compression
B	The minimum difference in dB between two signals which produce third-order intermodulation products greater than the noise floor
C	The minimum difference in dB between the levels of two FM signals that will cause one signal to block the other
D	The difference in dB between the noise floor and the third-order intercept point

20. - E4E10

What might be the cause of a loud roaring or buzzing AC line interference that comes and goes at intervals?

Select	Answer
A	A defective doorbell or doorbell transformer inside a nearby residence
B	A malfunctioning illuminated advertising display
C	Arcing contacts in a thermostatically controlled device
D	All these choices are correct

21. - E5A16

What is the resonant frequency of an RLC circuit if R is 33 ohms, L is 50 microhenries and C is 10 picofarads?

Select	Answer
A	23.5 kHz
B	23.5 MHz
C	7.12 MHz
D	7.12 kHz

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 in phase
C	Voltage leads current by 90 degrees
D	Voltage and current are 180 degrees out of phase

23. - E5C04

What coordinate system is often used to display the resistive, inductive, and/or capacitive reactance components of impedance?

Select	Answer
A	Faraday grid
B	Maidenhead grid
C	Rectangular coordinates
D	Elliptical coordinates

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	0.707
C	0.866
D	0.5

25. - E6A01

In what application is gallium arsenide used as a semiconductor material?

Select	Answer
A	In high-power audio circuits
B	In high-current rectifier circuits
C	In very low-frequency RF circuits
D	In microwave circuits

26. - E6B03

What type of bias is required for an LED to emit light?

Select	Answer
A	Inductive bias
B	Zero bias
C	Reverse bias
D	Forward bias

27. - E6C11

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

Select	Answer
A	6
B	2
C	5
D	4

28. - E6D08

What is one reason for using powdered-iron cores rather than ferrite cores in an inductor?

Select	Answer
A	Powdered-iron cores use smaller diameter wire for the same inductance
B	Powdered-iron cores generally require fewer turns to produce a given inductance
C	Powdered-iron cores generally have greater initial permeability
D	Powdered-iron cores generally maintain their characteristics at higher currents

29. - E6E01

Why is gallium arsenide (GaAs) useful for semiconductor devices operating at UHF and higher frequencies?

Select	Answer
A	Lower junction voltage drop
B	Higher electron mobility
C	Higher noise figures
D	Lower transconductance

30. - E6F03

What is the most common configuration of an optoisolator or optocoupler?

Select	Answer
A	A lens and a photomultiplier
B	A frequency modulated helium-neon laser
C	An amplitude modulated helium-neon laser
D	An LED and a phototransistor

31. - E7A03

Which of the following can divide the frequency of a pulse train by 2?

Select	Answer
A	An OR gate
B	A flip-flop
C	An XOR gate
D	A multiplexer

32. - E7B01

For what portion of the signal cycle does each active element in a push-pull Class AB amplifier conduct?

Select	Answer
A	The entire cycle
B	More than 180 degrees but less than 360 degrees
C	Exactly 180 degrees
D	Less than 180 degrees

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

34. - E7D10

What is the primary reason that a high-frequency switching type high-voltage power supply can be both less expensive and lighter in weight than a conventional power supply?

Select	Answer
A	The inverter design does not require any output filtering
B	The high frequency inverter design uses much smaller transformers and filter components for an equivalent power output
C	It uses a large power factor compensation capacitor to recover power from the unused portion of the AC cycle
D	It uses a diode bridge rectifier for increased output

35. - E7E07

What is meant by the term "baseband" in radio communications?

Select	Answer
A	The frequency range occupied by a message signal prior to modulation
B	The lowest frequency band that the transmitter or receiver covers
C	The basic oscillator frequency in an FM transmitter that is multiplied to increase the deviation and carrier frequency
D	The unmodulated bandwidth of the transmitted signal

36. - E7F04

What is a common method of generating an SSB signal using digital signal processing?

Select	Answer
A	Mixing products are converted to voltages and subtracted by adder circuits
B	Varying quartz crystal characteristics emulated in digital form
C	A frequency synthesizer removes the unwanted sidebands
D	Signals are combined in quadrature phase relationship

37. - E7G04

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

Select	Answer
A	The output voltage of the op-amp minus its input voltage
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 differential input voltage needed to bring the open loop output voltage to zero

38. - E7H02

What is a microphonic?

Select	Answer
A	Distortion caused by RF pickup on the microphone cable
B	Changes in oscillator frequency due to mechanical vibration
C	Excess loading of the microphone by an oscillator
D	An IC used for amplifying microphone signals

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 true-RMS calculating meter
C	An absorption wave meter
D	A grid dip meter

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

41. - E8C12

What factors affect the bandwidth of a transmitted CW signal?

Select	Answer
A	IF bandwidth and Q
B	Modulation index and output power
C	Keying speed and shape factor (rise and fall time)
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	Signal-to-noise ratio
B	Baud rate
C	Repeat Request Rate (RRR)
D	Intermodulation Distortion (IMD)

43. - E9A05

What is included in the total resistance of an antenna system?

Select	Answer
A	Radiation resistance plus space impedance
B	Radiation resistance plus transmission resistance
C	Transmission-line resistance plus radiation resistance
D	Radiation resistance plus loss resistance

44. - E9B05

What type of antenna pattern is shown in Figure E9-2?

Select	Answer
A	Elevation
B	Radiation resistance
C	Polarization
D	Azimuth

45. - E9C06

What is the effect of adding a terminating resistor to a rhombic antenna?

Select	Answer
A	It changes the radiation pattern from bidirectional to unidirectional
B	It reflects the standing waves on the antenna elements back to the transmitter
C	It changes the radiation pattern from horizontal to vertical polarization
D	It decreases the ground loss

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

47. - E9E07

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

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

48. - E9F07

How does ladder line compare to small-diameter coaxial cable such as RG-58 at 50 MHz?

Select	Answer
A	Lower velocity factor
B	Smaller reflection coefficient
C	Lower loss
D	Higher SWR

49. - E9G06

On the Smith chart shown in Figure E9-3, what is the name for the large outer circle on which the reactance arcs terminate?

Select	Answer
A	Prime axis
B	Reactance axis
C	Impedance axis
D	Polar axis

50. - E9H04

What is an advantage of placing a grounded electrostatic shield around a small loop direction-finding antenna?

Select	Answer
A	It eliminates tracking errors caused by strong out-of-band signals
B	It increases signal strength by providing a better match to the feed line
C	It adds capacitive loading, increasing the bandwidth of the antenna
D	It eliminates unbalanced capacitive coupling to the surroundings, improving the nulls

Figure E6-3

Figure E9-2

Figure E9-3