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

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1. - E0A06

Why are there separate electric (E) and magnetic (H) field MPE limits?

Select	Answer
A	E field and H field radiation intensity peaks can occur at different locations
B	All these choices are correct
C	Ground reflections and scattering make the field strength vary with location
D	The body reacts to electromagnetic radiation from both the E and H fields

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	14.149 MHz
B	14.349 MHz
C	14.100 MHz
D	14.070 MHz

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 except a Technician Class
C	Any FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)
D	Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served

4. - E1C01

What is the maximum bandwidth for a data emission on 60 meters?

Select	Answer
A	1.5 kHz
B	60 Hz
C	2.8 kHz
D	170 Hz

5. - E1D09

Which UHF amateur bands have frequencies authorized for space stations?

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

6. - E1E09

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

Select	Answer
A	All these choices are correct
B	A fine of up to $1000 per occurrence
C	Revocation of the VE's amateur station license grant and the suspension of the VE's amateur operator license grant
D	A sentence of up to one year in prison

7. - E1F11

Which of the following best describes one of the standards that must be met by an external RF power amplifier if it is to qualify for a grant of FCC certification?

Select	Answer
A	It must produce full legal output when driven by not more than 5 watts of mean RF input power
B	It must satisfy the FCC's spurious emission standards when operated at the lesser of 1500 watts or its full output power
C	It must exhibit a gain of 0 dB or less over its full output range
D	It must be capable of external RF switching between its input and output networks

8. - E2A01

What is the direction of an ascending pass for an amateur satellite?

Select	Answer
A	From west to east
B	From south to north
C	From north to south
D	From east to west

9. - E2B01

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

Select	Answer
A	90
B	120
C	60
D	30

10. - E2C04

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

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

11. - E2D09

What type of modulation is used for JT65 contacts?

Select	Answer
A	Multi-tone AFSK
B	RTTY
C	PSK
D	IEEE 802.11

12. - E2E06

What is the most common data rate used for HF packet?

Select	Answer
A	110 baud
B	300 baud
C	48 baud
D	1200 baud

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

14. - E3B04

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

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

15. - E3C04

What does the value of Bz (B sub Z) represent?

Select	Answer
A	Duration of long-delayed echoes
B	Critical frequency for vertical transmissions
C	Geomagnetic field stability
D	Direction and strength of the interplanetary magnetic field

16. - E4A05

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

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

17. - E4B04

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

Select	Answer
A	S22
B	S21
C	S11
D	S12

18. - E4C05

What does a receiver noise floor of -174 dBm represent?

Select	Answer
A	The noise figure of a 1 Hz bandwidth receiver
B	The theoretical noise in a 1 Hz bandwidth at the input of a perfect receiver at room temperature
C	The galactic noise contribution to minimum detectable signal
D	The minimum detectable signal as a function of receive frequency

19. - E4D02

Which of the following describes problems caused by poor dynamic range in a receiver?

Select	Answer
A	Oscillator instability and severe audio distortion of all but the strongest received signals
B	Oscillator instability requiring frequent retuning and loss of ability to recover the opposite sideband
C	Cross-modulation of the desired signal and insufficient audio power to operate the speaker
D	Spurious signals caused by cross-modulation and desensitization from strong adjacent signals

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

21. - E5A10

How is the Q of an RLC series resonant circuit calculated?

Select	Answer
A	Resistance divided by the reactance of either the inductance or capacitance
B	Reactance of either the inductance or capacitance multiplied by the resistance
C	Reactance of the inductance multiplied by the reactance of the capacitance
D	Reactance of either the inductance or capacitance divided by the resistance

22. - E5B01

What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the applied voltage or to discharge to 36.8% of its initial voltage?

Select	Answer
A	An exponential rate of one
B	One time constant
C	A time factor of one
D	One exponential period

23. - E5C07

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

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

24. - E5D08

How many watts are consumed in a circuit having a power factor of 0.6 if the input is 200VAC at 5 amperes?

Select	Answer
A	600 watts
B	1600 watts
C	1000 watts
D	200 watts

25. - E6A08

What term indicates the frequency at which the grounded-base current gain of a transistor has decreased to 0.7 of the gain obtainable at 1 kHz?

Select	Answer
A	Alpha rejection frequency
B	Beta cutoff frequency
C	Alpha cutoff frequency
D	Corner frequency

26. - E6B08

Which of the following is a Schottky barrier diode?

Select	Answer
A	Thermionic emission diode
B	PIN junction
C	Metal-semiconductor junction
D	Electrolytic rectifier

27. - E6C09

What is a Programmable Logic Device (PLD)?

Select	Answer
A	Programmable equipment used for testing digital logic integrated circuits
B	A programmable collection of logic gates and circuits in a single integrated circuit
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. - E6D09

What devices are commonly used as VHF and UHF parasitic suppressors at the input and output terminals of a transistor HF amplifier?

Select	Answer
A	Electrolytic capacitors
B	Steel-core toroids
C	Butterworth filters
D	Ferrite beads

29. - E6E09

Which of the following component package types would be most suitable for use at frequencies above the HF range?

Select	Answer
A	Axial lead
B	Surface mount
C	Radial lead
D	TO-220

30. - E6F02

What happens to the conductivity of a photoconductive material when light shines on it?

Select	Answer
A	It decreases
B	It becomes unstable
C	It stays the same
D	It increases

31. - E7A03

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

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

32. - E7B13

Which of the following describes an emitter follower (or common collector) amplifier?

Select	Answer
A	A differential amplifier with both inputs fed to the emitter of the input transistor
B	An OR circuit with only one emitter used for output
C	A two-transistor amplifier with the emitters sharing a common bias resistor
D	An amplifier with a low impedance output that follows the base input voltage

33. - E7C02

Which of the following is a property of a T-network with series capacitors and a parallel shunt inductor?

Select	Answer
A	It is a band-pass filter
B	It is a notch filter
C	It is a low-pass filter
D	It is a high-pass filter

34. - E7D06

What is the purpose of Q1 in the circuit shown in Figure E7-2?

Select	Answer
A	It provides D1 with current
B	It provides negative feedback to improve regulation
C	It provides a constant load for the voltage source
D	It controls the current supplied to the load

35. - E7E02

What is the function of a reactance modulator?

Select	Answer
A	To produce AM signals by using an electrically variable inductance or capacitance
B	To produce PM signals by using an electrically variable resistance
C	To produce AM signals by using an electrically variable resistance
D	To produce PM or FM signals by using an electrically variable inductance or capacitance

36. - E7F03

What type of digital signal processing filter is used to generate an SSB signal?

Select	Answer
A	An elliptical filter
B	A Hilbert-transform filter
C	An adaptive filter
D	A notch filter

37. - E7G06

What is the gain-bandwidth of an operational amplifier?

Select	Answer
A	The gain of the amplifier at a filter's cutoff frequency
B	The maximum frequency for a filter circuit using that type of amplifier
C	The frequency at which the amplifier's offset voltage is zero
D	The frequency at which the open-loop gain of the amplifier equals one

38. - E7H11

What are the major spectral impurity components of direct digital synthesizers?

Select	Answer
A	Broadband noise
B	Nyquist limit noise
C	Spurious signals at discrete frequencies
D	Digital conversion noise

39. - E8A09

How many different input levels can be encoded by an analog-to-digital converter with 8-bit resolution?

Select	Answer
A	256 divided by the gain of the input amplifier
B	256
C	8
D	8 multiplied by the gain of the input amplifier

40. - E8B07

Orthogonal Frequency Division Multiplexing is a technique used for which type of amateur communication?

Select	Answer
A	OFDM signals are not allowed on amateur bands
B	High-speed digital modes
C	EME
D	Extremely low-power contacts

41. - E8C08

How does ARQ accomplish error correction?

Select	Answer
A	Special polynomial codes provide automatic correction
B	If errors are detected, a retransmission is requested
C	If errors are detected, redundant data is substituted
D	Special binary codes provide automatic correction

42. - E8D11

What is one advantage of using ASCII code for data communications?

Select	Answer
A	It is possible to transmit both upper and lower case text
B	It uses one character as a shift code to send numeric and special characters
C	It includes built-in error correction features
D	It contains fewer information bits per character than any other code

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	2.79 dB
B	6.0 dB
C	3.85 dB
D	8.15 dB

44. - E9B10

What is the principle of a Method of Moments analysis?

Select	Answer
A	A wire is modeled as a series of segments, each having a uniform value of current
B	A wire is modeled as a single sine-wave voltage source
C	A wire is modeled as a single sine-wave current generator
D	A wire is modeled as a series of segments, each having a distinct value of voltage across it

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 align more in the direction of the wire
D	The lobes become more perpendicular to the wire

46. - E9D08

What happens as the Q of an antenna increases?

Select	Answer
A	SWR bandwidth decreases
B	More common-mode current is present on the feed line
C	SWR bandwidth increases
D	Gain is reduced

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

48. - E9F06

What is the approximate physical length of an air-insulated, parallel conductor transmission line that is electrically 1/2 wavelength long at 14.10 MHz?

Select	Answer
A	7.0 meters
B	13.3 meters
C	8.5 meters
D	10.6 meters

49. - E9G07

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

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

50. - E9H04

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

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

Figure E7-2

Figure E9-3