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	Polymorphic silicon
B	Polytetrafluoroethylene
C	Polyethylene
D	Polychlorinated biphenyls

2. - E1A03

What is the maximum legal carrier frequency on the 20 meter band for transmitting USB AFSK digital signals having a 1 kHz bandwidth?

Select	Answer
A	14.349 MHz
B	14.100 MHz
C	14.070 MHz
D	14.149 MHz

3. - E1B01

Which of the following constitutes a spurious emission?

Select	Answer
A	A signal transmitted to prevent its detection by any station other than the intended recipient
B	An amateur station transmission made without the proper call sign identification
C	An emission outside the signal's necessary bandwidth that can be reduced or eliminated without affecting the information transmitted
D	Any transmitted signal that unintentionally interferes with another licensed radio station

4. - E1C07

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

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

5. - E1D09

Which UHF amateur bands have frequencies authorized for space stations?

Select	Answer
A	70 cm and 13 cm
B	33 cm and 13 cm
C	70 cm only
D	70 cm and 33 cm

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

7. - E1F05

Amateur stations may not transmit in which of the following frequency segments if they are located in the contiguous 48 states and north of Line A?

Select	Answer
A	420 MHz - 430 MHz
B	53 MHz - 54 MHz
C	222 MHz - 223 MHz
D	440 MHz - 450 MHz

8. - E2A07

Which of the following types of signals can be relayed through a linear transponder?

Select	Answer
A	PSK and packet
B	SSB and SSTV
C	All these choices are correct
D	FM and CW

9. - E2B03

How is an interlaced scanning pattern generated in a fast-scan (NTSC) television system?

Select	Answer
A	By scanning odd numbered lines in one field and even numbered lines in the next
B	By scanning two fields simultaneously
C	By scanning lines from left to right in one field and right to left in the next
D	By scanning each field from bottom to top

10. - E2C01

What indicator is required to be used by U.S.-licensed operators when operating a station via remote control and the remote transmitter is located in the U.S.?

Select	Answer
A	/ followed by the ARRL Section of the remote station
B	No additional indicator is required
C	/ followed by the USPS two-letter abbreviation for the state in which the remote station is located
D	/R# where # is the district of the remote station

11. - E2D08

What type of packet frame is used to transmit APRS beacon data?

Select	Answer
A	Acknowledgement
B	Unnumbered Information
C	Connect
D	Disconnect

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	One of the signal filters is saturated
C	The receiver has drifted 5 kHz from the desired receive frequency
D	The mark and space signal have been inverted

13. - E3A14

What is meant by circularly polarized electromagnetic waves?

Select	Answer
A	Waves with a rotating electric field
B	Waves produced by a loop antenna
C	Waves with an electric field bent into a circular shape
D	Waves that circle the Earth

14. - E3B01

What is transequatorial propagation?

Select	Answer
A	Propagation between points at the same latitude
B	Propagation between a point on the equator and its antipodal point
C	Propagation between points located on the magnetic equator
D	Propagation between two mid-latitude points at approximately the same distance north and south of the magnetic equator

15. - E3C12

How does the maximum range of ground-wave propagation change when the signal frequency is increased?

Select	Answer
A	It stays the same
B	It decreases
C	It increases
D	It peaks at roughly 14 MHz

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

17. - E4B02

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

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

18. - E4C02

Which of the following receiver circuits can be effective in eliminating interference from strong out-of-band signals?

Select	Answer
A	A notch filter
B	A narrow IF filter
C	A front-end filter or pre-selector
D	A properly adjusted product detector

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	Adjacent channel interference
B	Neutralization
C	Amplifier desensitization
D	Intermodulation

20. - E4E06

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

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

21. - E5A11

What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150?

Select	Answer
A	23.67 kHz
B	315.6 Hz
C	157.8 Hz
D	47.3 kHz

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	Voltage and current are in phase
C	Voltage leads current by 90 degrees
D	Current leads voltage by 90 degrees

23. - E5C07

Where is the impedance of a pure resistance plotted on rectangular coordinates?

Select	Answer
A	On the vertical axis
B	On the horizontal axis
C	On a horizontal line, offset vertically above the horizontal axis
D	On a line through the origin, slanted at 45 degrees

24. - E5D03

What is microstrip?

Select	Answer
A	Short lengths of coax mounted on printed circuit boards to minimize time delay between microwave circuits
B	Miniature coax used for low power applications
C	Lightweight transmission line made of common zip cord
D	Precision printed circuit conductors above a ground plane that provide constant impedance interconnects at microwave frequencies

25. - E6A03

Why does a PN-junction diode not conduct current when reverse biased?

Select	Answer
A	Only P-type semiconductor material can conduct current
B	Excess holes in P-type material combine with the electrons in N-type material, converting the entire diode into an insulator
C	Only N-type semiconductor material can conduct current
D	Holes in P-type material and electrons in the N-type material are separated by the applied voltage, widening the depletion region

26. - E6B03

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

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

27. - E6C09

What is a Programmable Logic Device (PLD)?

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

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

29. - E6E10

What advantage does surface-mount technology offer at RF compared to using through-hole components?

Select	Answer
A	All these choices are correct
B	Shorter circuit-board traces
C	Smaller circuit area
D	Components have less parasitic inductance and capacitance

30. - E6F06

Which of these materials is most commonly used to create photoconductive devices?

Select	Answer
A	A heavy metal
B	An ordinary metal
C	A crystalline semiconductor
D	A liquid semiconductor

31. - E7A10

What is a truth table?

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

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

33. - E7C03

What advantage does a series-L Pi-L-network have over a series-L Pi-network for impedance matching between the final amplifier of a vacuum-tube transmitter and an antenna?

Select	Answer
A	Does not require a capacitor
B	Greater transformation range
C	Higher efficiency
D	Greater harmonic suppression

34. - E7D03

What device is typically used as a stable voltage reference in a linear voltage regulator?

Select	Answer
A	An SCR
B	A varactor diode
C	A Zener diode
D	A tunnel diode

35. - E7E03

What is a frequency discriminator stage in a FM receiver?

Select	Answer
A	An automatic band-switching circuit
B	An FM generator circuit
C	A circuit for filtering two closely adjacent signals
D	A circuit for detecting FM signals

36. - E7F05

How frequently must an analog signal be sampled by an analog-to-digital converter so that the signal can be accurately reproduced?

Select	Answer
A	At four times the rate of the highest frequency component of the signal
B	At least half the rate of the highest frequency component of the signal
C	At the same rate as the highest frequency component of the signal
D	At least twice the rate of the highest frequency component of the signal

37. - E7G08

How does the gain of an ideal operational amplifier vary with frequency?

Select	Answer
A	It decreases linearly with increasing frequency
B	It does not vary with frequency
C	It increases linearly with increasing frequency
D	It decreases logarithmically with increasing frequency

38. - E7H09

What type of frequency synthesizer circuit uses a phase accumulator, lookup table, digital to analog converter, and a low-pass anti-alias filter?

Select	Answer
A	A hybrid synthesizer
B	A direct digital synthesizer
C	A diode-switching matrix synthesizer
D	A phase-locked loop synthesizer

39. - E8A06

What is the approximate ratio of PEP-to-average power in a typical single-sideband phone signal?

Select	Answer
A	100 to 1
B	1 to 1
C	25 to 1
D	2.5 to 1

40. - E8B01

What is the modulation index of an FM signal?

Select	Answer
A	The ratio of frequency deviation to modulating signal frequency
B	The type of modulation used by the transmitter
C	The bandwidth of the transmitted signal divided by the modulating signal frequency
D	The ratio of modulating signal amplitude to frequency deviation

41. - E8C01

How is Forward Error Correction implemented?

Select	Answer
A	By varying the frequency shift of the transmitted signal according to a predefined algorithm
B	By transmitting a special algorithm to the receiving station along with the data characters
C	By transmitting extra data that may be used to detect and correct transmission errors
D	By the receiving station repeating each block of three data characters

42. - E8D05

What is the most common method of reducing key clicks?

Select	Answer
A	Reduce keying waveform rise and fall times
B	Low-pass filters at the transmitter output
C	High-pass filters at the transmitter output
D	Increase keying waveform rise and fall times

43. - E9A12

How much gain does an antenna have compared to a 1/2-wavelength dipole when it has 6 dB gain over an isotropic antenna?

Select	Answer
A	8.15 dB
B	2.79 dB
C	3.85 dB
D	6.0 dB

44. - E9B11

What is a disadvantage of decreasing the number of wire segments in an antenna model below 10 segments per half-wavelength?

Select	Answer
A	The computed feed point impedance may be incorrect
B	Ground conductivity will not be accurately modeled
C	The resulting design will favor radiation of harmonic energy
D	The antenna will become mechanically unstable

45. - E9C04

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

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

46. - E9D03

Where should a high Q loading coil be placed to minimize losses in a shortened vertical antenna?

Select	Answer
A	As low as possible on the vertical radiator
B	At a voltage node
C	Near the center of the vertical radiator
D	As close to the transmitter as possible

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 gamma match
B	The delta match
C	The stub 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	A capacitive reactance
B	The same as the characteristic impedance of the line
C	Zero
D	An inductive reactance

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	Polar axis
C	Impedance axis
D	Reactance axis

50. - E9H07

Why is RF attenuation used when direction-finding?

Select	Answer
A	To increase receiver sensitivity
B	To narrow the receiver bandwidth
C	To compensate for isotropic directivity and the antenna effect of feed lines
D	To prevent receiver overload which reduces pattern nulls

Figure E9-3