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

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1. - E0A05

What is one of the potential hazards of operating in the amateur radio microwave bands?

Select	Answer
A	Microwaves are ionizing radiation
B	Microwaves often travel long distances by ionospheric reflection
C	The extremely high frequency energy can damage the joints of antenna structures
D	The high gain antennas commonly used can result in high exposure levels

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	18.100 MHz
B	18.068 MHz
C	18.107 MHz
D	18.110 MHz

3. - E1B05

What is the National Radio Quiet Zone?

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

4. - E1C01

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

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

5. - E1D09

Which UHF amateur bands have frequencies authorized for space stations?

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

6. - E1E02

Who does Part 97 task with maintaining the pools of questions for all U.S. amateur license examinations?

Select	Answer
A	The VEs
B	The VECs
C	The ARRL
D	The FCC

7. - E1F09

Which of the following conditions apply when transmitting spread spectrum emissions?

Select	Answer
A	The transmission must not be used to obscure the meaning of any communication
B	All these choices are correct
C	A station transmitting SS emission must not cause harmful interference to other stations employing other authorized emissions
D	The transmitting station must be in an area regulated by the FCC or in a country that permits SS emissions

8. - E2A08

Why should effective radiated power to a satellite that uses a linear transponder be limited?

Select	Answer
A	To prevent the satellite from emitting out-of-band signals
B	To prevent creating errors in the satellite telemetry
C	To avoid reducing the downlink power to all other users
D	To avoid interfering with terrestrial QSOs

9. - E2B02

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

Select	Answer
A	525
B	30
C	60
D	1080

10. - E2C07

What is the Cabrillo format?

Select	Answer
A	A method of exchanging information during a contest QSO
B	The most common set of contest rules
C	The rules of order for meetings between contest sponsors
D	A standard for submission of electronic contest logs

11. - E2D08

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

Select	Answer
A	Acknowledgement
B	Disconnect
C	Connect
D	Unnumbered Information

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. - E3A09

Which of the following frequency ranges is most suited for meteor scatter communications?

Select	Answer
A	220 MHz - 450 MHz
B	10 MHz - 14 MHz
C	28 MHz - 148 MHz
D	1.8 MHz - 1.9 MHz

14. - E3B11

At what time of day can sporadic E propagation occur?

Select	Answer
A	Any time
B	Only in hours of darkness
C	Only around sunset
D	Only around sunset and sunrise

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	Eastward
D	Southward

16. - E4A04

How is the compensation of an oscilloscope probe typically adjusted?

Select	Answer
A	A DC voltage standard is displayed and the probe is adjusted until the displayed voltage is accurate
B	A square wave is displayed and the probe is adjusted until the horizontal portions of the displayed wave are as nearly flat as possible
C	A frequency standard is displayed and the probe is adjusted until the deflection time is accurate
D	A high frequency sine wave is displayed and the probe is adjusted for maximum amplitude

17. - E4B09

What is indicated if the current reading on an RF ammeter placed in series with the antenna feed line of a transmitter increases as the transmitter is tuned to resonance?

Select	Answer
A	There is an impedance mismatch between the antenna and feed line
B	The transmitter is not properly neutralized
C	There is possibly a short to ground in the feed line
D	There is more power going into the antenna

18. - E4C01

What is an effect of excessive phase noise in a receiver's local oscillator?

Select	Answer
A	It decreases receiver third-order intercept point
B	It can affect the receiver's frequency calibration
C	It limits the receiver's ability to receive strong signals
D	It can combine with strong signals on nearby frequencies to generate interference

19. - E4D11

Why are odd-order intermodulation products, created within a receiver, of particular interest compared to other products?

Select	Answer
A	Odd-order products of two signals in the band of interest are also likely to be within the band
B	Odd-order products are an indication of poor image rejection
C	Odd-order products overload the IF filters
D	Odd-order intermodulation produces three products for every input signal within the band of interest

20. - E4E06

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

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

21. - E5A05

What is the result of increasing the Q of an impedance-matching circuit?

Select	Answer
A	Matching range is increased
B	Matching bandwidth is decreased
C	It has no effect on impedance matching
D	Matching bandwidth is increased

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

23. - E5C05

What is the name of the diagram used to show the phase relationship between impedances at a given frequency?

Select	Answer
A	Venn diagram
B	Near field diagram
C	Phasor diagram
D	Far field diagram

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	1.42 mW
C	704 W
D	252 W

25. - E6A06

What is the beta of a bipolar junction transistor?

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

26. - E6B04

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

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

27. - E6C03

What is tri-state logic?

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

28. - E6D04

Which materials are commonly used as a core in an inductor?

Select	Answer
A	Polystyrene and polyethylene
B	Ferrite and brass
C	Teflon and Delrin
D	Cobalt and aluminum

29. - E6E03

Which of the following materials is likely to provide the highest frequency of operation when used in MMICs?

Select	Answer
A	Silicon
B	Gallium nitride
C	Silicon nitride
D	Silicon dioxide

30. - E6F03

What is the most common configuration of an optoisolator or optocoupler?

Select	Answer
A	An amplitude modulated helium-neon laser
B	A lens and a photomultiplier
C	An LED and a phototransistor
D	A frequency modulated helium-neon laser

31. - E7A08

What logical operation does an OR gate perform?

Select	Answer
A	It only produces logic 0 at its output when all inputs are logic 1
B	It produces logic 1 at its output if any or all inputs are logic 1
C	It produces logic 1 at its output if all inputs are logic 0
D	It produces logic 0 at its output if all inputs are logic 1

32. - E7B04

Where on the load line of a Class A common emitter amplifier would bias normally be set?

Select	Answer
A	At a point where the load line intersects the zero bias current curve
B	At a point where the bias resistor equals the load resistor
C	Where the load line intersects the voltage axis
D	Approximately halfway between saturation and cutoff

33. - E7C01

How are the capacitors and inductors of a low-pass filter Pi-network arranged between the network's input and output?

Select	Answer
A	A capacitor is connected between the input and ground, another capacitor is connected between the output and ground, and an inductor is connected between input and output
B	Two capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground
C	An inductor is connected between the input and ground, another inductor is connected between the output and ground, and a capacitor is connected between the input and output
D	Two inductors are in series between the input and output, and a capacitor is connected between the two inductors and ground

34. - E7D11

What is the function of the pass transistor in a linear voltage regulator circuit?

Select	Answer
A	Permits a wide range of output voltage settings
B	Provides a stable input impedance over a wide range of source voltage
C	Maintains nearly constant output voltage over a wide range of load current
D	Maintains nearly constant output impedance over a wide range of load current

35. - E7E07

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

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

36. - E7F13

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

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

37. - E7G12

What is an operational amplifier?

Select	Answer
A	A RF amplifier used in the UHF and microwave regions
B	An amplifier used to increase the average output of frequency modulated amateur signals to the legal limit
C	A high-gain, direct-coupled differential amplifier with very high input impedance and very low output impedance
D	A digital audio amplifier whose characteristics are determined by components external to the amplifier

38. - E7H02

What is a microphonic?

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

39. - E8A03

What type of wave does a Fourier analysis show to be made up of sine waves of a given fundamental frequency plus all its harmonics?

Select	Answer
A	A sawtooth wave
B	A cosine wave
C	A square wave
D	A sine wave

40. - E8B05

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus-or-minus 5 kHz when the maximum modulation frequency is 3 kHz?

Select	Answer
A	60
B	1.67
C	0.167
D	0.6

41. - E8C02

What is the definition of symbol rate in a digital transmission?

Select	Answer
A	The number of control characters in a message packet
B	The rate at which the waveform changes to convey information
C	The duration of each bit in a message sent over the air
D	The number of characters carried per second by the station-to-station link

42. - E8D03

How does the spread spectrum technique of frequency hopping work?

Select	Answer
A	If interference is detected by the receiver it will signal the transmitter to wait until the frequency is clear
B	A binary bit stream is used to shift the phase of an RF carrier very rapidly in a pseudorandom sequence
C	If interference is detected by the receiver it will signal the transmitter to change frequencies
D	The frequency of the transmitted signal is changed very rapidly according to a pseudorandom sequence also used by the receiving station

43. - E9A13

What term describes station output, taking into account all gains and losses?

Select	Answer
A	Half-power bandwidth
B	Effective radiated power
C	Power factor
D	Apparent power

44. - E9B04

What is the front-to-back ratio of the radiation pattern shown in Figure E92?

Select	Answer
A	15 dB
B	3 dB
C	38 dB
D	28 dB

45. - E9C09

Which of the following describes a G5RV antenna?

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

46. - E9D06

What happens to the SWR bandwidth when one or more loading coils are used to resonate an electrically short antenna?

Select	Answer
A	It is decreased
B	It is unchanged if the loading coil is located at the feed point
C	It is increased
D	It is unchanged if the loading coil is located at a voltage maximum point

47. - E9E10

Which of these choices is an effective way to match an antenna with a 100-ohm feed point impedance to a 50-ohm coaxial cable feed line?

Select	Answer
A	Connect a 1/2 wavelength shorted stub of 75-ohm cable in parallel with the 50-ohm cable where it attaches to the antenna
B	Insert a 1/2 wavelength piece of 300-ohm twinlead in series between the antenna terminals and the 50-ohm feed cable
C	Insert a 1/4-wavelength piece of 75-ohm coaxial cable transmission line in series between the antenna terminals and the 50-ohm feed cable
D	Connect a 1/4-wavelength open stub of 300-ohm twinlead in parallel with the coaxial feed line where it connects to the antenna

48. - E9F09

What is the approximate physical length of a foam polyethylene dielectric coaxial transmission line that is electrically 1/4 wavelength long at 7.2 MHz?

Select	Answer
A	5.2 meters
B	8.3 meters
C	10.4 meters
D	6.9 meters

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 impedance of a transmission line, given the physical dimensions
D	Determine the gain of an antenna given the physical and electrical parameters

50. - E9H01

When constructing a Beverage antenna, which of the following factors should be included in the design to achieve good performance at the desired frequency?

Select	Answer
A	It must be mounted more than 1 wavelength above ground
B	It should be one or more wavelengths long
C	It should be configured as a four-sided loop
D	Its overall length must not exceed 1/4 wavelength