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

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1. - E0A03

Over what range of frequencies are the FCC human body RF exposure limits most restrictive?

Select	Answer
A	3 to 30 MHz
B	300 kHz to 3 MHz
C	300 to 3000 MHz
D	30 to 300 MHz

2. - E1A01

Which of the following carrier frequencies is illegal for LSB AFSK emissions on the 17 meter band RTTY and data segment of 18.068 to 18.110 MHz?

Select	Answer
A	18.068 MHz
B	18.110 MHz
C	18.107 MHz
D	18.100 MHz

3. - E1B11

What does PRB-1 require of regulations affecting amateur radio?

Select	Answer
A	Amateur radio operations must be permitted in any private residence
B	Use of wireless devices in a vehicle is exempt from regulation
C	Reasonable accommodations of amateur radio must be made
D	No limitations may be placed on antenna size or placement

4. - E1C08

What is the maximum permissible duration of a remotely controlled station's transmissions if its control link malfunctions?

Select	Answer
A	3 minutes
B	30 seconds
C	10 minutes
D	5 minutes

5. - E1D03

What is a space telecommand station?

Select	Answer
A	An amateur station that receives telemetry from a satellite or balloon more than 50 kilometers above the surface of the Earth
B	An amateur station located on the surface of the Earth for communication with other Earth stations by means of Earth satellites
C	An amateur station that transmits communications to initiate, modify or terminate functions of a space station
D	An amateur station located in a satellite or a balloon more than 50 kilometers above the surface of the Earth

6. - E1E04

Which of the following best describes the Volunteer Examiner accreditation process?

Select	Answer
A	Each General, Advanced and Amateur Extra Class operator is automatically accredited as a VE when the license is granted
B	The prospective VE obtains accreditation from the FCC
C	The amateur operator applying must pass a VE examination administered by the FCC Enforcement Bureau
D	The procedure by which a VEC confirms that the VE applicant meets FCC requirements to serve as an examiner

7. - E1F03

Under what circumstances may a dealer sell an external RF power amplifier capable of operation below 144 MHz if it has not been granted FCC certification?

Select	Answer
A	It was purchased in used condition from an amateur operator and is sold to another amateur operator for use at that operator's station
B	It was imported from a manufacturer in another country and was certificated by that country's government
C	The equipment dealer assembled it from a kit
D	It was imported from a manufacturer in a country that does not require certification of RF power amplifiers

8. - E2A06

What are Keplerian elements?

Select	Answer
A	High-emission heater filaments used in magnetron tubes
B	Encrypting codes used for spread spectrum modulation
C	Phase reversing elements in a Yagi antenna
D	Parameters that define the orbit of a satellite

9. - E2B05

Which of the following describes the use of vestigial sideband in analog fast-scan TV transmissions?

Select	Answer
A	Vestigial sideband reduces bandwidth while allowing for simple video detector circuitry
B	The vestigial sideband carries the audio information
C	The vestigial sideband contains chroma information
D	Vestigial sideband provides high frequency emphasis to sharpen the picture

10. - E2C11

How should you generally identify your station when attempting to contact a DX station during a contest or in a pileup?

Select	Answer
A	Send the call sign of the DX station three times, the words this is,then your call sign three times
B	Send only the last two letters of your call sign until you make contact
C	Send your full call sign and grid square
D	Send your full call sign once or twice

11. - E2D05

What is one advantage of the JT65 mode?

Select	Answer
A	The ability to decode signals which have a very low signal-to-noise ratio
B	Easily copied by ear if necessary
C	Uses only a 65 Hz bandwidth
D	Permits fast-scan TV transmissions over narrow bandwidth

12. - E2E13

Which of these digital modes has the fastest data throughput under clear communication conditions?

Select	Answer
A	300 baud packet
B	170 Hz shift, 45 baud RTTY
C	PSK31
D	AMTOR

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 E layer
B	The F1 layer
C	The F2 layer
D	The D layer

14. - E3B10

Why is chordal hop propagation desirable?

Select	Answer
A	Atmospheric noise is lower in the direction of chordal hop propagation
B	The MUF for chordal hop propagation is much lower than for normal skip propagation
C	Signals travel faster along ionospheric chords
D	The signal experiences less loss compared to multi-hop using Earth as a reflector

15. - E3C14

Why does the radio-path horizon distance exceed the geometric horizon?

Select	Answer
A	Downward bending due to density variations in the atmosphere
B	D-region skip
C	Due to the Doppler effect
D	E-region skip

16. - E4A10

Which of the following displays multiple digital signal states simultaneously?

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

17. - E4B01

Which of the following factors most affects the accuracy of a frequency counter?

Select	Answer
A	Time base accuracy
B	Temperature coefficient of the logic
C	Decade divider accuracy
D	Input attenuator accuracy

18. - E4C07

What does the MDS of a receiver represent?

Select	Answer
A	The meter display sensitivity
B	The minimum discernible signal
C	The multiplex distortion stability
D	The maximum detectable spectrum

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 the levels of two FM signals that will cause one signal to block the other
C	The minimum difference in dB between two signals which produce third-order intermodulation products greater than the noise floor
D	The difference in dB between the noise floor and the third-order intercept point

20. - E4E09

What undesirable effect can occur when using an IF noise blanker?

Select	Answer
A	The audio frequency bandwidth of the received signal might be compressed
B	Received audio in the speech range might have an echo effect
C	Nearby signals may appear to be excessively wide even if they meet emission standards
D	FM signals can no longer be demodulated

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	7.12 kHz
B	7.12 MHz
C	23.5 kHz
D	23.5 MHz

22. - E5B02

What letter is commonly used to represent susceptance?

Select	Answer
A	X
B	B
C	Y
D	G

23. - E5C07

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

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

24. - E5D10

How can the true power be determined in an AC circuit where the voltage and current are out of phase?

Select	Answer
A	By dividing the apparent power by the power factor
B	By dividing the reactive power by the power factor
C	By multiplying the apparent power by the power factor
D	By multiplying the reactive power by the power factor

25. - E6A01

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

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

26. - E6B04

What type of semiconductor device is designed for use as a voltage-controlled capacitor?

Select	Answer
A	Varactor diode
B	Tunnel diode
C	Silicon-controlled rectifier
D	Zener diode

27. - E6C03

What is tri-state logic?

Select	Answer
A	Logic devices that utilize ternary math
B	Proprietary logic devices manufactured by Tri-State Devices
C	Logic devices with 0, 1, and high-impedance output states
D	Low-power logic devices designed to operate at 3 volts

28. - E6D13

What is the primary cause of inductor self-resonance?

Select	Answer
A	Inter-turn capacitance
B	The skin effect
C	Inductive kickback
D	Non-linear core hysteresis

29. - E6E02

Which of the following device packages is a through-hole type?

Select	Answer
A	DIP
B	PLCC
C	SOT
D	Ball grid array

30. - E6F08

Why are optoisolators often used in conjunction with solid-state circuits when switching 120 VAC?

Select	Answer
A	Optoisolators provide impedance matching between the control circuit and power circuit
B	Optoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched
C	Optoisolators provide a low impedance link between a control circuit and a power circuit
D	Optoisolators eliminate the effects of reflected light in the control circuit

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. - E7B11

In Figure E7-1, what is the purpose of R3?

Select	Answer
A	Output load resistor
B	Emitter bypass
C	Fixed bias
D	Self bias

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

34. - E7D03

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

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

35. - E7E06

Why is de-emphasis commonly used in FM communications receivers?

Select	Answer
A	For higher efficiency
B	For compatibility with transmitters using phase modulation
C	To reduce impulse noise reception
D	To remove third-order distortion products

36. - E7F01

What is meant by direct digital conversion as applied to software defined radios?

Select	Answer
A	Incoming RF is digitized by an analog-to-digital converter without being mixed with a local oscillator signal
B	A switching mixer is used to generate I and Q signals directly from the RF input
C	Software is converted from source code to object code during operation of the receiver
D	Incoming RF is converted to a control voltage for a voltage controlled oscillator

37. - E7G11

What absolute voltage gain can be expected from the circuit in Figure E7-3 when R1 is 3300 ohms and RF is 47 kilohms?

Select	Answer
A	28
B	0.07
C	14
D	7

38. - E7H13

Which of the following is a technique for providing highly accurate and stable oscillators needed for microwave transmission and reception?

Select	Answer
A	Use a rubidium stabilized reference oscillator
B	All these choices are correct
C	Use a GPS signal reference
D	Use a temperature-controlled high Q dielectric resonator

39. - E8A09

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

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

40. - E8B03

What is the modulation index of an FM-phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency when the modulating frequency is 1000 Hz?

Select	Answer
A	3000
B	0.3
C	1000
D	3

41. - E8C10

How may data rate be increased without increasing bandwidth?

Select	Answer
A	Using a more efficient digital code
B	Increasing analog-to-digital conversion resolution
C	Using forward error correction
D	It is impossible

42. - E8D08

What parameter evaluates distortion of an AFSK signal caused by excessive input audio levels?

Select	Answer
A	Intermodulation Distortion (IMD)
B	Repeat Request Rate (RRR)
C	Baud rate
D	Signal-to-noise ratio

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	The input power level
C	Antenna height
D	Transmission line length

44. - E9B09

What type of computer program technique is commonly used for modeling antennas?

Select	Answer
A	Method of Moments
B	Graphical analysis
C	Calculus differentiation with respect to physical properties
D	Mutual impedance analysis

45. - E9C10

Which of the following describes a Zepp antenna?

Select	Answer
A	A vertical array capable of quickly changing the direction of maximum radiation by changing phasing lines
B	An end-fed dipole antenna
C	An omni-directional antenna commonly used for satellite communications
D	A dipole constructed from zip cord

46. - E9D05

What usually occurs if a Yagi antenna is designed solely for maximum forward gain?

Select	Answer
A	The SWR is reduced
B	The front-to-back ratio decreases
C	The frequency response is widened over the whole frequency band
D	The front-to-back ratio increases

47. - E9E03

What is the name of the matching system that uses a section of transmission line connected in parallel with the feed line at or near the feed point?

Select	Answer
A	The delta match
B	The gamma match
C	The stub match
D	The omega match

48. - E9F02

Which of the following has the biggest effect on the velocity factor of a transmission line?

Select	Answer
A	The center conductor resistivity
B	The line length
C	Dielectric materials used in the line
D	The termination impedance

49. - E9G05

Which of the following is a common use for a Smith chart?

Select	Answer
A	Determine the length and position of an impedance matching stub
B	Determine the loss/100 feet of a transmission line, given the velocity factor and conductor materials
C	Determine the gain of an antenna given the physical and electrical parameters
D	Determine the impedance of a transmission line, given the physical dimensions

50. - E9H05

What is the main drawback of a small wire-loop antenna for direction finding?

Select	Answer
A	It is practical for use only on VHF and higher bands
B	It has a bidirectional pattern
C	All these choices are correct
D	It has no clearly defined null

Figure E7-1

Figure E7-3