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

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1. - E0A04

When evaluating a site with multiple transmitters operating at the same time, the operators and licensees of which transmitters are responsible for mitigating over-exposure situations?

Select	Answer
A	Only commercial transmitters
B	Only the most powerful transmitter
C	Each transmitter operating with a duty cycle greater than 50 percent
D	Each transmitter that produces 5 percent or more of its MPE limit in areas where the total MPE limit is exceeded.

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

3. - E1B02

Which of the following is an acceptable bandwidth for Digital Radio Mondiale (DRM) based voice or SSTV digital transmissions made on the HF amateur bands?

Select	Answer
A	3 kHz
B	10 kHz
C	15 kHz
D	20 kHz

4. - E1C08

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

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

5. - E1D02

Which of the following may transmit special codes intended to obscure the meaning of messages?

Select	Answer
A	Auxiliary relay links carrying repeater audio
B	Data containing personal information
C	Binary control characters
D	Telecommand signals from a space telecommand station

6. - E1E05

What is the minimum passing score on all amateur operator license examinations?

Select	Answer
A	Minimum passing score of 74%
B	Minimum passing score of 70%
C	Minimum passing score of 80%
D	Minimum passing score of 77%

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

8. - E2A12

What is the purpose of digital store-and-forward functions on an amateur radio satellite?

Select	Answer
A	To delay download of telemetry between satellites
B	To upload operational software for the transponder
C	To relay messages between satellites
D	To store digital messages in the satellite for later download by other stations

9. - E2B02

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

Select	Answer
A	60
B	525
C	1080
D	30

10. - E2C10

Why might a DX station state that they are listening on another frequency?

Select	Answer
A	Because the DX station may be transmitting on a frequency that is prohibited to some responding stations
B	To separate the calling stations from the DX station
C	All these choices are correct
D	To improve operating efficiency by reducing interference

11. - E2D11

Which of the following data are used by the APRS network to communicate station location?

Select	Answer
A	Radio direction finding spectrum analysis
B	Latitude and longitude
C	Polar coordinates
D	Time and frequency

12. - E2E12

How do ALE stations establish contact?

Select	Answer
A	ALE radios activate when they hear their signal echoed by back scatter
B	ALE radios monitor an internet site for the frequency they are being paged on
C	ALE radios send a constant tone code to establish a frequency for future use
D	ALE constantly scans a list of frequencies, activating the radio when the designated call sign is received

13. - E3A09

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

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

14. - E3B06

Which of the following amateur bands most frequently provides long-path propagation?

Select	Answer
A	6 meters
B	10 meters
C	80 meters
D	20 meters

15. - E3C08

What does the space weather term G5 mean?

Select	Answer
A	Waning sunspot numbers
B	Moderate solar wind
C	Very low solar activity
D	An extreme geomagnetic storm

16. - E4A05

What is the purpose of the prescaler function on a frequency counter?

Select	Answer
A	It prevents oscillation in a low-frequency counter circuit
B	It divides a higher frequency signal so a low-frequency counter can display the input frequency
C	It amplifies low-level signals for more accurate counting
D	It multiplies a higher frequency signal so a low-frequency counter can display the operating frequency

17. - E4B03

Which S parameter is equivalent to forward gain?

Select	Answer
A	S22
B	S11
C	S12
D	S21

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

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. - E4E08

What current flows equally on all conductors of an unshielded multi-conductor cable?

Select	Answer
A	Differential-mode current
B	Common-mode current
C	Return current
D	Reactive current only

21. - E5A15

Which of the following increases Q for inductors and capacitors?

Select	Answer
A	Lower reactance
B	Higher self-resonant frequency
C	Lower self-resonant frequency
D	Lower losses

22. - E5B01

What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the applied voltage or to discharge to 36.8% of its initial voltage?

Select	Answer
A	A time factor of one
B	One exponential period
C	One time constant
D	An exponential rate of one

23. - E5C01

Which of the following represents capacitive reactance in rectangular notation?

Select	Answer
A	+jX
B	Omega
C	Delta
D	-jX

24. - E5D03

What is microstrip?

Select	Answer
A	Lightweight transmission line made of common zip cord
B	Precision printed circuit conductors above a ground plane that provide constant impedance interconnects at microwave frequencies
C	Short lengths of coax mounted on printed circuit boards to minimize time delay between microwave circuits
D	Miniature coax used for low power applications

25. - E6A09

What is a depletion-mode FET?

Select	Answer
A	Any FET without a channel
B	An FET that exhibits a current flow between source and drain when no gate voltage is applied
C	An FET that has no current flow between source and drain when no gate voltage is applied
D	Any FET for which holes are the majority carriers

26. - E6B06

Which of the following is a common use of a Schottky diode?

Select	Answer
A	As a VHF/UHF mixer or detector
B	As a constant voltage reference in a power supply
C	As a variable capacitance in an automatic frequency control circuit
D	As a rectifier in high current power supplies

27. - E6C09

What is a Programmable Logic Device (PLD)?

Select	Answer
A	A type of transistor whose gain can be changed by digital logic circuits
B	A programmable collection of logic gates and circuits in a single integrated circuit
C	Programmable equipment used for testing digital logic integrated circuits
D	A logic circuit that can be modified during use

28. - E6D07

What is current in the primary winding of a transformer called if no load is attached to the secondary?

Select	Answer
A	Direct current
B	Magnetizing current
C	Excitation current
D	Stabilizing current

29. - E6E06

What characteristics of the MMIC make it a popular choice for VHF through microwave circuits?

Select	Answer
A	Nearly infinite gain, very high input impedance, and very low output impedance
B	Plate current that is controlled by a control grid
C	The ability to retrieve information from a single signal even in the presence of other strong signals
D	Controlled gain, low noise figure, and constant input and output impedance over the specified frequency range

30. - E6F05

Which describes an optical shaft encoder?

Select	Answer
A	A device that measures the strength of a beam of light using analog to digital conversion
B	A device for generating RTTY signals by means of a rotating light source
C	A device that detects rotation of a control by interrupting a light source with a patterned wheel
D	A digital encryption device often used to encrypt spacecraft control signals

31. - E7A11

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

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

32. - E7B01

For what portion of the signal cycle does each active element in a push-pull Class AB amplifier conduct?

Select	Answer
A	Less than 180 degrees
B	More than 180 degrees but less than 360 degrees
C	The entire cycle
D	Exactly 180 degrees

33. - E7C05

Which filter type is described as having ripple in the passband and a sharp cutoff?

Select	Answer
A	A passive op-amp filter
B	An active LC filter
C	A Butterworth filter
D	A Chebyshev filter

34. - E7D13

What is the equation for calculating power dissipated by a series linear voltage regulator?

Select	Answer
A	Input voltage divided by output current
B	Voltage difference from input to output multiplied by output current
C	Output voltage multiplied by output current
D	Input voltage multiplied by input current

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 basic oscillator frequency in an FM transmitter that is multiplied to increase the deviation and carrier frequency
D	The frequency range occupied by a message signal prior to modulation

36. - E7F07

What function is performed by a Fast Fourier Transform?

Select	Answer
A	Converting digital signals to analog form
B	Converting analog signals to digital form
C	Converting 8-bit data to 16-bit data
D	Converting digital signals from the time domain to the frequency domain

37. - E7G06

What is the gain-bandwidth of an operational amplifier?

Select	Answer
A	The frequency at which the amplifier's offset voltage is zero
B	The frequency at which the open-loop gain of the amplifier equals one
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. - E7H11

What are the major spectral impurity components of direct digital synthesizers?

Select	Answer
A	Broadband noise
B	Spurious signals at discrete frequencies
C	Digital conversion noise
D	Nyquist limit noise

39. - E8A07

What determines the PEP-to-average power ratio of a single-sideband phone signal?

Select	Answer
A	Amplifier gain
B	Speech characteristics
C	The degree of carrier suppression
D	The frequency of the modulating signal

40. - E8B09

What is deviation ratio?

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

41. - E8C07

What is the bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?

Select	Answer
A	4.8 kHz
B	9.6 kHz
C	5.76 kHz
D	15.36 kHz

42. - E8D06

What is the advantage of including parity bits in ASCII characters?

Select	Answer
A	Foreign language characters can be sent
B	Faster transmission rate
C	Some types of errors can be detected
D	The signal can overpower interfering signals

43. - E9A13

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

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

44. - E9B01

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

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

45. - E9C01

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed 180 degrees out of phase?

Select	Answer
A	Omni-directional
B	A figure-8 oriented along the axis of the array
C	Cardioid
D	A figure-8 broadside to the axis of the array

46. - E9D12

Which of the following would provide the best RF ground for your station?

Select	Answer
A	An electrically short connection to a metal water pipe
B	A 50-ohm resistor connected to ground
C	An electrically short connection to 3 or 4 interconnected ground rods via a series RF choke
D	An electrically short connection to 3 or 4 interconnected ground rods driven into the Earth

47. - E9E11

What is the primary purpose of phasing lines when used with an antenna having multiple driven elements?

Select	Answer
A	It allows single-band antennas to operate on other bands
B	It creates a low-angle radiation pattern
C	It prevents reflected power from traveling back down the feed line and causing harmonic radiation from the transmitter
D	It ensures that each driven element operates in concert with the others to create the desired antenna pattern

48. - E9F08

Which of the following is a significant difference between foam dielectric coaxial cable and solid dielectric cable, assuming all other parameters are the same?

Select	Answer
A	Foam dielectric has lower loss per unit of length
B	All these choices are correct
C	Foam dielectric has higher velocity factor
D	Foam dielectric has lower safe operating voltage limits

49. - E9G07

On the Smith chart shown in Figure E9-3, what is the only straight line shown?

Select	Answer
A	The resistance axis
B	The voltage axis
C	The reactance axis
D	The current axis

50. - E9H09

What is a Pennant antenna?

Select	Answer
A	A small, vertically oriented receiving antenna consisting of a triangular loop terminated in approximately 900 ohms
B	A stealth antenna built to look like a flagpole
C	A four-element, high-gain vertical array invented by George Pennant
D	A form of rhombic antenna terminated in a variable capacitor to provide frequency diversity

Figure E9-1

Figure E9-3