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

Logging in (or registering) will help the system to select questions that you need to focus on.

1. - E0A11

Which of the following injuries can result from using high-power UHF or microwave transmitters?

Select	Answer
A	Ingestion of ozone gas from the cooling system
B	Blood clotting from the intense magnetic field
C	Localized heating of the body from RF exposure in excess of the MPE limits
D	Hearing loss caused by high voltage corona discharge

2. - E1A05

What is the maximum power output permitted on the 60 meter band?

Select	Answer
A	100 watts PEP effective radiated power relative to the gain of a half-wave dipole
B	50 watts PEP effective radiated power relative to a dipole
C	100 watts PEP effective radiated power relative to an isotropic radiator
D	50 watts PEP effective radiated power relative to an isotropic radiator

3. - E1B03

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

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

4. - E1C11

Which of the following operating arrangements allows an FCC-licensed U.S. citizen to operate in many European countries, and alien amateurs from many European countries to operate in the U.S.?

Select	Answer
A	CEPT agreement
B	ITU reciprocal license
C	IARP agreement
D	All these choices are correct

5. - E1D08

Which VHF amateur bands have frequencies authorized for space stations?

Select	Answer
A	2 meters and 1.25 meters
B	2 meters
C	6 meters and 2 meters
D	6 meters, 2 meters, and 1.25 meters

6. - E1E02

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

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

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

8. - E2A07

Which of the following types of signals can be relayed through a linear transponder?

Select	Answer
A	All these choices are correct
B	FM and CW
C	PSK and packet
D	SSB and SSTV

9. - E2B02

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

Select	Answer
A	1080
B	525
C	60
D	30

10. - E2C06

During a VHF/UHF contest, in which band segment would you expect to find the highest level of SSB or CW activity?

Select	Answer
A	At the top of each band, usually in a segment reserved for contests
B	In the middle of the band, usually 25 kHz above the national calling frequency
C	In the middle of each band, usually on the national calling frequency
D	In the weak signal segment of the band, with most of the activity near the calling frequency

11. - E2D09

What type of modulation is used for JT65 contacts?

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

12. - E2E03

How is the timing of FT4 contacts organized?

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

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 gradual loss of signal as the sun rises
C	A slow change in the pitch of the CW signal
D	A fluttery irregular fading

14. - E3B07

What happens to linearly polarized radio waves that split into ordinary and extraordinary waves in the ionosphere?

Select	Answer
A	They become elliptically polarized
B	They become phase locked
C	They are bent toward the magnetic poles
D	They become depolarized

15. - E3C09

How does the intensity of an X3 flare compare to that of an X2 flare?

Select	Answer
A	50 percent greater
B	Four times as great
C	Twice as great
D	10 percent greater

16. - E4A03

Which of the following test instruments is used to display spurious signals and/or intermodulation distortion products generated by an SSB transmitter?

Select	Answer
A	A wattmeter
B	A spectrum analyzer
C	A logic analyzer
D	A time-domain reflectometer

17. - E4B02

What is the significance of voltmeter sensitivity expressed in ohms per volt?

Select	Answer
A	When used as an ammeter, the full scale reading in amps divided by ohms per volt rating will determine the size of shunt needed
B	When used as an ohmmeter, the reading in ohms divided by the ohms per volt rating will determine the voltage applied to the circuit
C	The full scale reading of the voltmeter multiplied by its ohms per volt rating will indicate the input impedance of the voltmeter
D	When used as a galvanometer, the reading in volts multiplied by the ohms per volt rating will determine the power drawn by the device under test

18. - E4C08

An SDR receiver is overloaded when input signals exceed what level?

Select	Answer
A	One-half the maximum sampling buffer size
B	The reference voltage of the analog-to-digital converter
C	One-half the maximum sample rate
D	The maximum count value of the analog-to-digital converter

19. - E4D02

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

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

20. - E4E07

Which of the following can cause shielded cables to radiate or receive interference?

Select	Answer
A	Common-mode currents on the shield and conductors
B	Low inductance ground connections at both ends of the shield
C	Tying all ground connections to a common point resulting in differential-mode currents in the shield
D	Use of braided shielding material

21. - E5A11

What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150?

Select	Answer
A	47.3 kHz
B	157.8 Hz
C	315.6 Hz
D	23.67 kHz

22. - E5B09

What is the relationship between the AC current through a capacitor and the voltage across a capacitor?

Select	Answer
A	Voltage leads current by 90 degrees
B	Current leads voltage by 90 degrees
C	Voltage and current are 180 degrees out of phase
D	Voltage and current are in phase

23. - E5C06

What does the impedance 50-j25 represent?

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

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	200 watts
B	1000 watts
C	600 watts
D	1600 watts

25. - E6A12

Why do many MOSFET devices have internally connected Zener diodes on the gates?

Select	Answer
A	To reduce the chance of static damage to the gate
B	To protect the substrate from excessive voltages
C	To provide a voltage reference for the correct amount of reverse-bias gate voltage
D	To keep the gate voltage within specifications and prevent the device from overheating

26. - E6B09

What is a common use for point-contact diodes?

Select	Answer
A	As a constant current source
B	As a constant voltage source
C	As a high-voltage rectifier
D	As an RF detector

27. - E6C11

In Figure E6-3, what is the schematic symbol for the NOT operation (inverter)?

Select	Answer
A	5
B	6
C	4
D	2

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

29. - E6E12

Why are DIP through-hole package ICs not typically used at UHF and higher frequencies?

Select	Answer
A	Epoxy coating is conductive above 300 MHz
B	Excessive lead length
C	Too many pins
D	Unsuitable for combining analog and digital signals

30. - E6F01

What absorbs the energy from light falling on a photovoltaic cell?

Select	Answer
A	Protons
B	Photons
C	Electrons
D	Holes

31. - E7A04

How many flip-flops are required to divide a signal frequency by 4?

Select	Answer
A	2
B	4
C	8
D	1

32. - E7B02

What is a Class D amplifier?

Select	Answer
A	A low power amplifier that uses a differential amplifier for improved linearity
B	A frequency doubling amplifier
C	A type of amplifier that uses switching technology to achieve high efficiency
D	An amplifier that uses drift-mode FETs for high efficiency

33. - E7C06

What are the distinguishing features of an elliptical filter?

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

34. - E7D11

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

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

35. - E7E05

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

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

36. - E7F03

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

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

37. - E7G06

What is the gain-bandwidth of an operational amplifier?

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

38. - E7H10

What information is contained in the lookup table of a direct digital synthesizer (DDS)?

Select	Answer
A	The phase relationship between a reference oscillator and the output waveform
B	The phase relationship between a voltage-controlled oscillator and the output waveform
C	Amplitude values that represent the desired waveform
D	Frequently used receiver and transmitter frequencies

39. - E8A05

What of the following instruments would be the most accurate for measuring the RMS voltage of a complex waveform?

Select	Answer
A	A grid dip meter
B	A true-RMS calculating meter
C	A D'Arsonval meter
D	An absorption wave meter

40. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

Select	Answer
A	A frequency modulation technique that uses non-harmonically related frequencies
B	A digital mode for narrow-band, slow-speed transmissions
C	A bandwidth compression technique using Fourier transforms
D	A digital modulation technique using subcarriers at frequencies chosen to avoid intersymbol interference

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

42. - E8D01

Why are received spread spectrum signals resistant to interference?

Select	Answer
A	The high power used by a spread spectrum transmitter keeps its signal from being easily overpowered
B	Signals not using the spread spectrum algorithm are suppressed in the receiver
C	The receiver is always equipped with a digital blanker
D	If interference is detected by the receiver it will signal the transmitter to change frequencies

43. - E9A09

What is antenna efficiency?

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

44. - E9B05

What type of antenna pattern is shown in Figure E9-2?

Select	Answer
A	Polarization
B	Radiation resistance
C	Elevation
D	Azimuth

45. - E9C14

How does the performance of a horizontally polarized antenna mounted on the side of a hill compare with the same antenna mounted on flat ground?

Select	Answer
A	The main lobe takeoff angle increases in the downhill direction
B	The main lobe takeoff angle decreases in the downhill direction
C	The horizontal beamwidth decreases in the downhill direction
D	The horizontal beamwidth increases in the uphill direction

46. - E9D04

Why should an HF mobile antenna loading coil have a high ratio of reactance to resistance?

Select	Answer
A	To minimize the Q
B	To lower the radiation angle
C	To minimize losses
D	To swamp out harmonics

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

48. - E9F11

What impedance does a 1/8-wavelength transmission line present to a generator when the line is open at the far end?

Select	Answer
A	An inductive reactance
B	The same as the characteristic impedance of the line
C	Infinite
D	A capacitive reactance

49. - E9G09

What third family of circles is often added to a Smith chart during the process of solving problems?

Select	Answer
A	Antenna-length circles
B	Radiation-pattern circles
C	Standing wave ratio circles
D	Coaxial-length circles

50. - E9H08

What is the function of a sense antenna?

Select	Answer
A	It increases the sensitivity of a DF antenna array
B	It provides diversity reception that cancels multipath signals
C	It modifies the pattern of a DF antenna array to provide a null in one direction
D	It allows DF antennas to receive signals at different vertical angles

Figure E6-3

Figure E9-2