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

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1. - E0A11

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

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

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

3. - E1B01

Which of the following constitutes a spurious emission?

Select	Answer
A	An emission outside the signal's necessary bandwidth that can be reduced or eliminated without affecting the information transmitted
B	A signal transmitted to prevent its detection by any station other than the intended recipient
C	An amateur station transmission made without the proper call sign identification
D	Any transmitted signal that unintentionally interferes with another licensed radio station

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 identify in the official language of the country in which you are operating
B	You must append "/CEPT" to your call sign
C	The U.S. embassy must approve of your operation
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 only
B	70 cm and 33 cm
C	33 cm and 13 cm
D	70 cm and 13 cm

6. - E1E03

What is a Volunteer Examiner Coordinator?

Select	Answer
A	A person who has volunteered to prepare amateur operator license examinations
B	An organization that has entered into an agreement with the FCC to coordinate, prepare, and administer amateur operator license examinations
C	A person who has volunteered to administer amateur operator license examinations
D	The person who has entered into an agreement with the FCC to be the VE session manager

7. - E1F04

Which of the following geographic descriptions approximately describes "Line A"?

Select	Answer
A	A line roughly parallel to and south of the border between the U.S. and Canada
B	A line roughly parallel to and west of the U.S. Atlantic coastline
C	A line roughly parallel to and east of the U.S. Pacific coastline
D	A line roughly parallel to and north of the border between the U.S. and Mexico

8. - E2A01

What is the direction of an ascending pass for an amateur satellite?

Select	Answer
A	From west to east
B	From north to south
C	From east to west
D	From south to north

9. - E2B09

What hardware, other than a receiver with SSB capability and a suitable computer, is needed to decode SSTV using Digital Radio Mondiale (DRM)?

Select	Answer
A	A special front end limiter
B	A special IF converter
C	A special notch filter to remove synchronization pulses
D	No other hardware is needed

10. - E2C01

What indicator is required to be used by U.S.-licensed operators when operating a station via remote control and the remote transmitter is located in the U.S.?

Select	Answer
A	/ followed by the USPS two-letter abbreviation for the state in which the remote station is located
B	No additional indicator is required
C	/ followed by the ARRL Section of the remote station
D	/R# where # is the district of the remote station

11. - E2D10

How can an APRS station be used to help support a public service communications activity?

Select	Answer
A	An APRS station with an emergency medical technician can automatically transmit medical data to the nearest hospital
B	An APRS station with a Global Positioning System unit can automatically transmit information to show a mobile station's position during the event
C	All these choices are correct
D	APRS stations with General Personnel Scanners can automatically relay the participant numbers and time as they pass the check points

12. - E2E03

How is the timing of FT4 contacts organized?

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

13. - E3A13

Which of these emission modes is best for auroral propagation?

Select	Answer
A	CW
B	RTTY
C	FM
D	SSB

14. - E3B11

At what time of day can sporadic E propagation occur?

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

15. - E3C04

What does the value of Bz (B sub Z) represent?

Select	Answer
A	Duration of long-delayed echoes
B	Geomagnetic field stability
C	Critical frequency for vertical transmissions
D	Direction and strength of the interplanetary magnetic field

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

17. - E4B07

What do the subscripts of S parameters represent?

Select	Answer
A	The relative time between measurements
B	Relative quality of the data
C	Frequency order of the measurements
D	The port or ports at which measurements are made

18. - E4C03

What is the term for the suppression in an FM receiver of one signal by another stronger signal on the same frequency?

Select	Answer
A	Frequency discrimination
B	Desensitization
C	Cross-modulation interference
D	Capture effect

19. - E4D02

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

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

20. - E4E01

What problem can occur when using an automatic notch filter (ANF) to remove interfering carriers while receiving CW signals?

Select	Answer
A	Received CW signals will appear to be modulated at the DSP clock frequency
B	Ringing in the DSP filter will completely remove the spaces between the CW characters
C	Removal of the CW signal as well as the interfering carrier
D	Any nearby signal passing through the DSP system will overwhelm the desired signal

21. - E5A03

What is the magnitude of the impedance of a series RLC circuit at resonance?

Select	Answer
A	Approximately equal to circuit resistance
B	Approximately equal to capacitive reactance
C	High, as compared to the circuit resistance
D	Approximately equal to inductive reactance

22. - E5B12

What is admittance?

Select	Answer
A	The inverse of impedance
B	The inverse of Q factor
C	The turns ratio of a transformer
D	The term for the gain of a field effect transistor

23. - E5C09

When using rectangular coordinates to graph the impedance of a circuit, what do the axes represent?

Select	Answer
A	The X axis represents the reactive component and the Y axis represents the resistive component
B	The X axis represents the resistive component and the Y axis represents the reactive component
C	The X axis represents the phase angle and the Y axis represents the magnitude
D	The X axis represents the magnitude and the Y axis represents the phase angle

24. - E5D13

How many watts are consumed in a circuit consisting of a 100-ohm resistor in series with a 100-ohm inductive reactance drawing 1 ampere?

Select	Answer
A	141.4 watts
B	70.7 watts
C	100 watts
D	200 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	Alpha rejection frequency
B	Alpha cutoff frequency
C	Beta cutoff frequency
D	Corner frequency

26. - E6B01

What is the most useful characteristic of a Zener diode?

Select	Answer
A	An internal capacitance that varies with the applied voltage
B	A constant current drop under conditions of varying voltage
C	A negative resistance region
D	A constant voltage drop under conditions of varying current

27. - E6C11

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

Select	Answer
A	6
B	4
C	5
D	2

28. - E6D11

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

Select	Answer
A	Ferrite
B	Ceramic
C	Brass
D	Powdered iron

29. - E6E02

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

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

30. - E6F02

What happens to the conductivity of a photoconductive material when light shines on it?

Select	Answer
A	It increases
B	It stays the same
C	It decreases
D	It becomes unstable

31. - E7A11

What type of logic defines "1" as a high voltage?

Select	Answer
A	Reverse Logic
B	Positive Logic
C	Assertive Logic
D	Negative logic

32. - E7B13

Which of the following describes an emitter follower (or common collector) amplifier?

Select	Answer
A	An OR circuit with only one emitter used for output
B	A differential amplifier with both inputs fed to the emitter of the input transistor
C	A two-transistor amplifier with the emitters sharing a common bias resistor
D	An amplifier with a low impedance output that follows the base input voltage

33. - E7C04

How does an impedance-matching circuit transform a complex impedance to a resistive impedance?

Select	Answer
A	It introduces negative resistance to cancel the resistive part of impedance
B	It introduces transconductance to cancel the reactive part of impedance
C	It cancels the reactive part of the impedance and changes the resistive part to a desired value
D	Reactive currents are dissipated in matched resistances

34. - E7D09

What is the main reason to use a charge controller with a solar power system?

Select	Answer
A	Matching of day and night charge rates
B	Control of electrolyte levels during battery discharge
C	Prevention of battery damage due to overcharge
D	Prevention of battery undercharge

35. - E7E08

What are the principal frequencies that appear at the output of a mixer circuit?

Select	Answer
A	The square root of the product of input frequencies
B	1.414 and 0.707 times the input frequency
C	Two and four times the original frequency
D	The two input frequencies along with their sum and difference frequencies

36. - E7F11

What sets the minimum detectable signal level for a direct-sampling SDR receiver in the absence of atmospheric or thermal noise?

Select	Answer
A	Reference voltage level and sample width in bits
B	Missing codes and jitter
C	Sample clock phase noise
D	Data storage transfer rate

37. - E7G09

What will be the output voltage of the circuit shown in Figure E7-3 if R1 is 1000 ohms, RF is 10,000 ohms, and 0.23 volts DC is applied to the input?

Select	Answer
A	0.23 volts
B	-2.3 volts
C	2.3 volts
D	-0.23 volts

38. - E7H07

How can an oscillator's microphonic responses be reduced?

Select	Answer
A	Increase the bias voltage
B	Reduce noise on the oscillator's power supply
C	Mechanically isolate the oscillator circuitry from its enclosure
D	Use NP0 capacitors

39. - E8A06

What is the approximate ratio of PEP-to-average power in a typical single-sideband phone signal?

Select	Answer
A	100 to 1
B	1 to 1
C	25 to 1
D	2.5 to 1

40. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

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

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	All these choices are correct
C	To improve carrier suppression
D	To minimize bandwidth

42. - E8D03

How does the spread spectrum technique of frequency hopping work?

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

43. - E9A04

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

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

44. - E9B02

In the antenna radiation pattern shown in Figure E9-1, what is the front-to-back ratio?

Select	Answer
A	36 dB
B	18 dB
C	14 dB
D	24 dB

45. - E9C13

How does the radiation pattern of a horizontally polarized 3-element beam antenna vary with increasing height above ground?

Select	Answer
A	The horizontal beamwidth increases
B	The takeoff angle of the lowest elevation lobe decreases
C	The takeoff angle of the lowest elevation lobe increases
D	The horizontal beamwidth decreases

46. - E9D02

How can linearly polarized Yagi antennas be used to produce circular polarization?

Select	Answer
A	Arrange two Yagis collinear to each other with the driven elements fed 180 degrees out of phase
B	Stack two Yagis fed 90 degrees out of phase to form an array with the respective elements in parallel planes
C	Stack two Yagis fed in phase to form an array with the respective elements in parallel planes
D	Arrange two Yagis perpendicular to each other with the driven elements at the same point on the boom fed 90 degrees out of phase

47. - E9E04

What is the purpose of the series capacitor in a gamma-type antenna matching network?

Select	Answer
A	To cancel the inductive reactance of the matching network
B	To provide DC isolation between the feed line and the antenna
C	To provide a rejection notch that prevents the radiation of harmonics
D	To transform the antenna impedance to a higher value

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 low impedance
C	Very high impedance
D	The same as the input impedance to the generator

49. - E9G04

What are the two families of circles and arcs that make up a Smith chart?

Select	Answer
A	Resistance and voltage
B	Reactance and voltage
C	Resistance and reactance
D	Voltage and impedance

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

Figure E6-3

Figure E7-3

Figure E9-1