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

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1. - E0A01

What is the primary function of an external earth connection or ground rod?

Select	Answer
A	Reduce received noise
B	Reduce RF current flow between pieces of equipment
C	Reduce RFI to telephones and home entertainment systems
D	Lightning protection

2. - E1A06

Where must the carrier frequency of a CW signal be set to comply with FCC rules for 60 meter operation?

Select	Answer
A	At the center frequency of the channel
B	On any frequency where the signal's sidebands are within the channel
C	At the lowest frequency of the channel
D	At the highest frequency of the channel

3. - E1B05

What is the National Radio Quiet Zone?

Select	Answer
A	An area in New Mexico surrounding the White Sands Test Area
B	An area in Florida surrounding Cape Canaveral
C	An area in Puerto Rico surrounding the Arecibo Radio Telescope
D	An area surrounding the National Radio Astronomy Observatory

4. - E1C02

Which of the following types of communications may be transmitted to amateur stations in foreign countries?

Select	Answer
A	Communications incidental to the purpose of the amateur service and remarks of a personal nature
B	All these choices are correct
C	Business-related messages for non-profit organizations
D	Messages intended for users of the maritime satellite service

5. - E1D07

Which HF amateur bands have frequencies authorized for space stations?

Select	Answer
A	Only the 40, 20, 17, 15, and 10 meter bands
B	Only the 40, 20, 17, 15, 12, and 10 meter bands
C	Only the 40, 30, 20, 15, 12, and 10 meter bands
D	All HF bands

6. - E1E08

To which of the following examinees may a VE not administer an examination?

Select	Answer
A	Employees of the VE
B	Friends of the VE
C	Relatives of the VE as listed in the FCC rules
D	All these choices are correct

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

8. - E2A09

What do the terms L band and S band specify regarding satellite communications?

Select	Answer
A	The 23 centimeter and 13 centimeter bands
B	FM and Digital Store-and-Forward systems
C	The 2 meter and 70 centimeter bands
D	Which sideband to use

9. - E2B02

How many horizontal lines make up a fast-scan (NTSC) television frame?

Select	Answer
A	30
B	525
C	1080
D	60

10. - E2C05

What is the function of a DX QSL Manager?

Select	Answer
A	To handle the receiving and sending of confirmation cards for a DX station
B	To run a net to allow many stations to contact a rare DX station
C	To relay calls to and from a DX station
D	To allocate frequencies for DXpeditions

11. - E2D04

What technology is used to track, in real time, balloons carrying amateur radio transmitters?

Select	Answer
A	Doppler shift of beacon signals
B	APRS
C	Bandwidth compressed LORAN
D	Ultrasonics

12. - E2E06

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

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

13. - E3A07

Atmospheric ducts capable of propagating microwave signals often form over what geographic feature?

Select	Answer
A	Bodies of water
B	Forests
C	Urban areas
D	Mountain ranges

14. - E3B12

What is the primary characteristic of chordal hop propagation?

Select	Answer
A	Propagation across the geomagnetic equator
B	Successive ionospheric refractions without an intermediate reflection from the ground
C	Propagation away from the great circle bearing between stations
D	Signals reflected back toward the transmitting station

15. - E3C05

What orientation of Bz (B sub z) increases the likelihood that incoming particles from the sun will cause disturbed conditions?

Select	Answer
A	Northward
B	Westward
C	Southward
D	Eastward

16. - E4A01

Which of the following limits the highest frequency signal that can be accurately displayed on a digital oscilloscope?

Select	Answer
A	Q of the circuit
B	All these choices are correct
C	Sampling rate of the analog-to-digital converter
D	Amount of memory

17. - E4B05

What three test loads are used to calibrate an RF vector network analyzer?

Select	Answer
A	50 ohms through 1/8 wavelength, 1/4 wavelength, and 1/2 wavelength of coaxial cable
B	Short circuit, open circuit, and resonant circuit
C	Short circuit, open circuit, and 50 ohms
D	50 ohms, 75 ohms, and 90 ohms

18. - E4C09

Which of the following choices is a good reason for selecting a high frequency for the design of the IF in a superheterodyne HF or VHF communications receiver?

Select	Answer
A	Fewer components in the receiver
B	Improved receiver noise figure
C	Easier for front-end circuitry to eliminate image responses
D	Reduced drift

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	Amplifier desensitization
B	Neutralization
C	Intermodulation
D	Adjacent channel interference

20. - E4E02

Which of the following types of noise can often be reduced with a digital signal processing noise filter?

Select	Answer
A	Broadband white noise
B	Ignition noise
C	All these choices are correct
D	Power line noise

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 MHz
B	23.5 kHz
C	7.12 MHz
D	7.12 kHz

22. - E5B06

What is susceptance?

Select	Answer
A	A measure of the efficiency of a transformer
B	The magnetic impedance of a circuit
C	The ratio of magnetic field to electric field
D	The imaginary part of admittance

23. - E5C03

Which of the following represents an inductive reactance in polar coordinates?

Select	Answer
A	A positive phase angle
B	A negative magnitude
C	A negative phase angle
D	A positive magnitude

24. - E5D07

How many watts are consumed in a circuit having a power factor of 0.71 if the apparent power is 500VA?

Select	Answer
A	355 W
B	252 W
C	1.42 mW
D	704 W

25. - E6A06

What is the beta of a bipolar junction transistor?

Select	Answer
A	The breakdown voltage of the base to collector junction
B	The switching speed
C	The change in collector current with respect to base current
D	The frequency at which the current gain is reduced to 0.707

26. - E6B10

In Figure E6-2, what is the schematic symbol for a light-emitting diode?

Select	Answer
A	5
B	7
C	6
D	1

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	A logic circuit that can be modified during use
C	Programmable equipment used for testing digital logic integrated circuits
D	A type of transistor whose gain can be changed by digital logic circuits

28. - E6D05

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

Select	Answer
A	Ferrite toroids generally have lower initial permeability
B	Ferrite toroids are easier to use with surface mount technology
C	Ferrite toroids generally have better temperature stability
D	Ferrite toroids generally require fewer turns to produce a given inductance value

29. - E6E01

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

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

30. - E6F10

What is the most common type of photovoltaic cell used for electrical power generation?

Select	Answer
A	Selenium
B	Cadmium Sulfide
C	Copper oxide
D	Silicon

31. - E7A10

What is a truth table?

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

32. - E7B10

In Figure E7-1, what is the purpose of R1 and R2?

Select	Answer
A	Load resistors
B	Voltage divider bias
C	Self bias
D	Feedback

33. - E7C06

What are the distinguishing features of an elliptical filter?

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

34. - E7D01

How does a linear electronic voltage regulator work?

Select	Answer
A	It has a ramp voltage as its output
B	The control element duty cycle is proportional to the line or load conditions
C	It eliminates the need for a pass transistor
D	The conduction of a control element is varied to maintain a constant output voltage

35. - E7E07

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

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

36. - E7F13

What is the function of taps in a digital signal processing filter?

Select	Answer
A	Select the point at which baseband signals are generated
B	To reduce excess signal pressure levels
C	Provide access for debugging software
D	Provide incremental signal delays for filter algorithms

37. - E7G04

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

Select	Answer
A	The potential between the amplifier input terminals of the op-amp in an open loop condition
B	The difference between the output voltage of the op-amp and the input voltage required in the immediately following stage
C	The differential input voltage needed to bring the open loop output voltage to zero
D	The output voltage of the op-amp minus its input voltage

38. - E7H02

What is a microphonic?

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

39. - E8A04

What is "dither" with respect to analog-to-digital converters?

Select	Answer
A	An error caused by irregular quantization step size
B	A small amount of noise added to the input signal to allow more precise representation of a signal over time
C	A method of decimation by randomly skipping samples
D	An abnormal condition where the converter cannot settle on a value to represent the signal

40. - E8B09

What is deviation ratio?

Select	Answer
A	The ratio of the carrier center frequency to the audio modulating frequency
B	The ratio of the highest audio modulating frequency to the average audio modulating frequency
C	The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency
D	The ratio of the audio modulating frequency to the center carrier frequency

41. - E8C03

Why should phase-shifting of a PSK signal be done at the zero crossing of the RF signal?

Select	Answer
A	To simplify modulation
B	To minimize bandwidth
C	All these choices are correct
D	To improve carrier suppression

42. - E8D04

What is the primary effect of extremely short rise or fall time on a CW signal?

Select	Answer
A	Limits data speed
B	The generation of key clicks
C	More difficult to copy
D	The generation of RF harmonics

43. - E9A09

What is antenna efficiency?

Select	Answer
A	Radiation resistance divided by total resistance
B	Radiation resistance divided by transmission resistance
C	Total resistance divided by radiation resistance
D	Effective radiated power divided by transmitter output

44. - E9B01

In the antenna radiation pattern shown in Figure E9-1, what is the beamwidth?

Select	Answer
A	25 degrees
B	50 degrees
C	30 degrees
D	75 degrees

45. - E9C09

Which of the following describes a G5RV antenna?

Select	Answer
A	A wide band dipole using shorted coaxial cable for the radiating elements and fed with a�4:1 balun
B	A multi-band trap antenna
C	A phased array antenna consisting of multiple loops
D	A multi-band dipole antenna fed with coax and a balun through a selected length of open wire transmission line

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. - E9E06

Which of these feed line impedances would be suitable for constructing a quarter-wave Q-section for matching a 100-ohm loop to 50-ohm feed line?

Select	Answer
A	62 ohms
B	75 ohms
C	450 ohms
D	50 ohms

48. - E9F12

What impedance does a 1/4-wavelength transmission line present to a generator when the line is open at the far end?

Select	Answer
A	The same as the characteristic impedance of the line
B	Very high impedance
C	Very low impedance
D	The same as the input impedance to the generator

49. - E9G10

What do the arcs on a Smith chart represent?

Select	Answer
A	Points with constant resistance
B	Frequency
C	Points with constant reactance
D	SWR

50. - E9H02

Which is generally true for low band (160 meter and 80 meter) receiving antennas?

Select	Answer
A	Low loss coax transmission line is essential for good performance
B	They must be erected at least 1/2 wavelength above the ground to attain good directivity
C	All these choices are correct
D	Atmospheric noise is so high that gain over a dipole is not important

Figure E6-2

Figure E7-1

Figure E9-1