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

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1. - E0A04

When evaluating a site with multiple transmitters operating at the same time, the operators and licensees of which transmitters are responsible for mitigating over-exposure situations?

Select	Answer
A	Each transmitter that produces 5 percent or more of its MPE limit in areas where the total MPE limit is exceeded.
B	Only commercial transmitters
C	Each transmitter operating with a duty cycle greater than 50 percent
D	Only the most powerful transmitter

2. - E1A09

What action or actions should you take if your digital message forwarding station inadvertently forwards a communication that violates FCC rules?

Select	Answer
A	All these choices are correct
B	Notify the nearest FCC Field Engineers office
C	Notify the originating station that the communication does not comply with FCC rules
D	Discontinue forwarding the communication as soon as you become aware of it

3. - E1B03

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

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

4. - E1C06

Which of the following is required in order to operate in accordance with CEPT rules in foreign countries where permitted?

Select	Answer
A	You must append "/CEPT" to your call sign
B	The U.S. embassy must approve of your operation
C	You must identify in the official language of the country in which you are operating
D	You must bring a copy of FCC Public Notice DA 16-1048

5. - E1D09

Which UHF amateur bands have frequencies authorized for space stations?

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

6. - E1E05

What is the minimum passing score on all amateur operator license examinations?

Select	Answer
A	Minimum passing score of 70%
B	Minimum passing score of 77%
C	Minimum passing score of 74%
D	Minimum passing score of 80%

7. - E1F08

Which of the following types of amateur station communications are prohibited?

Select	Answer
A	Communications that have religious content
B	Communications transmitted for hire or material compensation, except as otherwise provided in the rules
C	Communications in a language other than English
D	Communications that have political content, except as allowed by the Fairness Doctrine

8. - E2A04

What is meant by the term mode? as applied to an amateur radio satellite?

Select	Answer
A	Whether the satellite is in a low earth or geostationary orbit
B	The satellite's uplink and downlink frequency bands
C	The satellite's orientation with respect to the Earth
D	Whether the satellite is in a polar or equatorial orbit

9. - E2B10

What aspect of an analog slow-scan television signal encodes the brightness of the picture?

Select	Answer
A	Sync amplitude
B	Tone amplitude
C	Sync frequency
D	Tone frequency

10. - E2C03

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

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

11. - E2D11

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

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

12. - E2E03

How is the timing of FT4 contacts organized?

Select	Answer
A	Stations take turns on alternate days
B	Alternating transmissions at 7.5 second intervals
C	It depends on the lunar phase
D	By exchanging ACK/NAK packets

13. - E3A02

What characterizes libration fading of an EME signal?

Select	Answer
A	The returning echo is several hertz lower in frequency than the transmitted signal
B	A slow change in the pitch of the CW signal
C	A fluttery irregular fading
D	A gradual loss of signal as the sun rises

14. - E3B06

Which of the following amateur bands most frequently provides long-path propagation?

Select	Answer
A	10 meters
B	6 meters
C	20 meters
D	80 meters

15. - E3C15

What might be indicated by a sudden rise in radio background noise across a large portion of the HF spectrum?

Select	Answer
A	A temperature inversion has occurred
B	Long-path propagation is likely
C	Increased transequatorial propagation is likely
D	A solar flare has occurred

16. - E4A10

Which of the following displays multiple digital signal states simultaneously?

Select	Answer
A	Bit error rate tester
B	Network analyzer
C	Modulation monitor
D	Logic analyzer

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	75 watts
B	125 watts
C	100 watts
D	25 watts

18. - E4C06

A CW receiver with the AGC off has an equivalent input noise power density of -174 dBm/Hz. What would be the level of an unmodulated carrier input to this receiver that would yield an audio output SNR of 0 dB in a 400 Hz noise bandwidth?

Select	Answer
A	-155 dBm
B	-148 dBm
C	-174 dBm
D	-164 dBm

19. - E4D09

What is the purpose of the preselector in a communications receiver?

Select	Answer
A	To store often-used frequencies
B	To increase rejection of signals outside the desired band
C	To provide a range of AGC time constants
D	To allow selection of the optimum RF amplifier device

20. - E4E03

Which of the following signals might a receiver noise blanker be able to remove from desired signals?

Select	Answer
A	Signals that are constant at all IF levels
B	Signals that appear across a wide bandwidth
C	Signals that appear at one IF but not another
D	Signals that have a sharply peaked frequency distribution

21. - E5A10

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

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

22. - E5B08

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 100 ohms, R is 100 ohms, and XL is 75 ohms?

Select	Answer
A	14 degrees with the voltage leading the current
B	14 degrees with the voltage lagging the current
C	76 degrees with the voltage lagging the current
D	76 degrees with the voltage leading the current

23. - E5C06

What does the impedance 50-j25 represent?

Select	Answer
A	50 ohms resistance in series with 25 ohms capacitive reactance
B	25 ohms resistance in series with 50 ohms inductive reactance
C	50 ohms resistance in series with 25 ohms inductive reactance
D	25 ohms resistance in series with 50 ohms capacitive reactance

24. - E5D12

How many watts are consumed in a circuit having a power factor of 0.2 if the input is 100 VAC at 4 amperes?

Select	Answer
A	50 watts
B	2000 watts
C	80 watts
D	400 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	Corner frequency
B	Alpha cutoff frequency
C	Alpha rejection frequency
D	Beta cutoff frequency

26. - E6B08

Which of the following is a Schottky barrier diode?

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

27. - E6C02

What happens when the level of a comparator's input signal crosses the threshold?

Select	Answer
A	The feedback loop becomes unstable
B	The comparator changes its output state
C	The comparator enters latch-up
D	The IC input can be damaged

28. - E6D11

Which type of core material decreases inductance when inserted into a coil?

Select	Answer
A	Brass
B	Powdered iron
C	Ferrite
D	Ceramic

29. - E6E10

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

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

30. - E6F04

What is the photovoltaic effect?

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

31. - E7A06

What is a characteristic of a monostable multivibrator?

Select	Answer
A	It stores one bit of data in either a 0 or 1 state
B	It produces a continuous square wave oscillating between 1 and 0
C	It maintains a constant output voltage, regardless of variations in the input voltage
D	It switches momentarily to the opposite binary state and then returns to its original state after a set time

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

33. - E7C06

What are the distinguishing features of an elliptical filter?

Select	Answer
A	Gradual passband rolloff with minimal stop band ripple
B	Gradual passband rolloff with extreme stop band ripple
C	Extremely sharp cutoff with one or more notches in the stop band
D	Extremely flat response over its pass band with gradually rounded stop band corners

34. - E7D03

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

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

35. - E7E05

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

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

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 least half the rate of the highest frequency component of the signal
B	At least twice 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 four times the rate of the highest frequency component of the signal

37. - E7G03

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

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

38. - E7H05

How is positive feedback supplied in a Pierce oscillator?

Select	Answer
A	Through a neutralizing capacitor
B	Through link coupling
C	Through a quartz crystal
D	Through a tapped coil

39. - E8A11

Which of the following is a measure of the quality of an analog-to-digital converter?

Select	Answer
A	Power factor
B	Peak envelope power
C	Reciprocal mixing
D	Total harmonic distortion

40. - E8B02

How does the modulation index of a phase-modulated emission vary with RF carrier frequency?

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

41. - E8C07

What is the bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?

Select	Answer
A	9.6 kHz
B	15.36 kHz
C	4.8 kHz
D	5.76 kHz

42. - E8D07

What is a common cause of overmodulation of AFSK signals?

Select	Answer
A	Excessive transmit audio levels
B	Bit errors in the modem
C	Ground loops
D	Excessive numbers of retries

43. - E9A04

Which of the following factors affect the feed point impedance of an antenna?

Select	Answer
A	The settings of an antenna tuner at the transmitter
B	Transmission line length
C	Antenna height
D	The input power level

44. - E9B10

What is the principle of a Method of Moments analysis?

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

45. - E9C12

Which of the following describes an Extended Double Zepp antenna?

Select	Answer
A	An end-fed folded dipole antenna
B	A portable antenna erected using two push support poles
C	A center-fed 1.25-wavelength antenna (two 5/8-wave elements in phase)
D	A wideband vertical antenna constructed from precisely tapered aluminum tubing

46. - E9D01

How much does the gain of an ideal parabolic dish antenna change when the operating frequency is doubled?

Select	Answer
A	3 dB
B	2 dB
C	4 dB
D	6 dB

47. - E9E01

What system matches a higher-impedance transmission line to a lower-impedance antenna by connecting the line to the driven element in two places spaced a fraction of a wavelength each side of element center?

Select	Answer
A	The omega matching system
B	The gamma matching system
C	The delta matching system
D	The stub matching system

48. - E9F05

What is the approximate physical length of a solid polyethylene dielectric coaxial transmission line that is electrically 1/4 wavelength long at 14.1 MHz?

Select	Answer
A	10.6 meters
B	5.3 meters
C	3.5 meters
D	4.3 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. - E9H11

What feature of a cardioid pattern antenna makes it useful for direction finding?

Select	Answer
A	High radiation angle
B	A very sharp single null
C	Broadband response
D	A very sharp peak

Figure E9-3