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

2. - E1A05

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

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

3. - E1B04

What must be done before placing an amateur station within an officially designated wilderness area or wildlife preserve, or an area listed in the National Register of Historic Places?

Select	Answer
A	A proposal must be submitted to the National Park Service
B	A letter of intent must be filed with the Environmental Protection Agency
C	An Environmental Assessment must be submitted to the FCC
D	A form FSD-15 must be submitted to the Department of the Interior

4. - E1C03

How do the control operator responsibilities of a station under automatic control differ from one under local control?

Select	Answer
A	Under automatic control there is no control operator
B	Under local control a control operator is not required to be present at a control point
C	Under automatic control the control operator is not required to be present at the control point
D	Under local control there is no control operator

5. - E1D05

What must be posted at the station location of a station being operated by telecommand on or within 50 km of the earth's surface?

Select	Answer
A	A label with the name, address, and telephone number of the station licensee
B	A photocopy of the station license
C	All these choices are correct
D	A label with the name, address, and telephone number of the control operator

6. - E1E01

For which types of out-of-pocket expenses do the Part 97 rules state that VEs and VECs may be reimbursed?

Select	Answer
A	Teaching an amateur operator license examination preparation course
B	No expenses are authorized for reimbursement
C	Providing amateur operator license examination preparation training materials
D	Preparing, processing, administering, and coordinating an examination for an amateur radio operator license

7. - E1F10

Who may be the control operator of an auxiliary station?

Select	Answer
A	Only Amateur Extra Class operators
B	Any licensed amateur operator
C	Only Technician, General, Advanced or Amateur Extra Class operators
D	Only General, Advanced or Amateur Extra Class operators

8. - E2A10

What type of satellite appears to stay in one position in the sky?

Select	Answer
A	LEO
B	HEO
C	Geostationary
D	Geomagnetic

9. - E2B02

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

Select	Answer
A	1080
B	60
C	525
D	30

10. - E2C04

Which of the following frequencies are sometimes used for amateur radio mesh networks?

Select	Answer
A	The 60 meter band channel centered on 5373 kHz
B	Cable TV channels 41 through 43
C	Frequencies shared with various unlicensed wireless data services
D	HF frequencies where digital communications are permitted

11. - E2D10

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

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

12. - E2E12

How do ALE stations establish contact?

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

13. - E3A13

Which of these emission modes is best for auroral propagation?

Select	Answer
A	RTTY
B	CW
C	SSB
D	FM

14. - E3B04

What is meant by the terms "extraordinary" and "ordinary" waves?

Select	Answer
A	Independent waves created in the ionosphere that are elliptically polarized
B	Refracted rays and reflected waves
C	Extraordinary waves describe rare long-skip propagation compared to ordinary waves, which travel shorter distances
D	Long-path and short-path waves

15. - E3C13

What type of polarization is best for ground-wave propagation?

Select	Answer
A	Elliptical
B	Vertical
C	Circular
D	Horizontal

16. - E4A04

How is the compensation of an oscilloscope probe typically adjusted?

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

17. - E4B07

What do the subscripts of S parameters represent?

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

18. - E4C14

What transmit frequency might generate an image response signal in a receiver tuned to 14.300 MHz and that uses a 455 kHz IF frequency?

Select	Answer
A	14.755 MHz
B	13.845 MHz
C	15.210 MHz
D	14.445 MHz

19. - E4D12

What is the term for the reduction in receiver sensitivity caused by a strong signal near the received frequency?

Select	Answer
A	Desensitization
B	Quieting
C	Cross-modulation interference
D	Squelch gain rollback

20. - E4E03

Which of the following signals might a receiver noise blanker be able to remove from desired signals?

Select	Answer
A	Signals that are constant at all IF levels
B	Signals that have a sharply peaked frequency distribution
C	Signals that appear at one IF but not another
D	Signals that appear across a wide bandwidth

21. - E5A01

What can cause the voltage across reactances in a series RLC circuit to be higher than the voltage applied to the entire circuit?

Select	Answer
A	Resistance
B	Capacitance
C	Resonance
D	Conductance

22. - E5B10

What is the relationship between the AC current through an inductor and the voltage across an inductor?

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

23. - E5C06

What does the impedance 50-j25 represent?

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

24. - E5D03

What is microstrip?

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

25. - E6A05

How does DC input impedance at the gate of a field-effect transistor compare with the DC input impedance of a bipolar transistor?

Select	Answer
A	They are both low impedance
B	They are both high impedance
C	An FET has lower input impedance
D	An FET has higher input impedance

26. - E6B03

What type of bias is required for an LED to emit light?

Select	Answer
A	Inductive bias
B	Zero bias
C	Reverse bias
D	Forward bias

27. - E6C08

In Figure E6-3, what is the schematic symbol for a NAND gate?

Select	Answer
A	1
B	2
C	3
D	4

28. - E6D01

Why should core saturation of an impedance matching transformer be avoided?

Select	Answer
A	Harmonics and distortion could result
B	Temporary changes of the core permeability could result
C	RF susceptance would increase
D	Magnetic flux would increase with frequency

29. - E6E12

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

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

30. - E6F05

Which describes an optical shaft encoder?

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

31. - E7A10

What is a truth table?

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

32. - E7B15

What is one way to prevent thermal runaway in a bipolar transistor amplifier?

Select	Answer
A	All these choices are correct
B	Select transistors with high beta
C	Use a resistor in series with the emitter
D	Neutralization

33. - E7C07

Which describes a Pi-L-network used for matching a vacuum tube final amplifier to a 50-ohm unbalanced output?

Select	Answer
A	A Phase Inverter Load network
B	A network with only three discrete parts
C	A matching network in which all components are isolated from ground
D	A Pi-network with an additional series inductor on the output

34. - E7D15

What is the purpose of a step-start circuit in a high-voltage power supply?

Select	Answer
A	To provide a dual-voltage output for reduced power applications
B	To compensate for variations of the incoming line voltage
C	To allow for remote control of the power supply
D	To allow the filter capacitors to charge gradually

35. - E7E06

Why is de-emphasis commonly used in FM communications receivers?

Select	Answer
A	For higher efficiency
B	To reduce impulse noise reception
C	For compatibility with transmitters using phase modulation
D	To remove third-order distortion products

36. - E7F09

Why is an anti-aliasing digital filter required in a digital decimator?

Select	Answer
A	It peaks the response of the decimator, improving bandwidth
B	It removes high-frequency signal components that would otherwise be reproduced as lower frequency components
C	It notches out the sampling frequency to avoid sampling errors
D	It removes low-frequency signal components to eliminate the need for DC restoration

37. - E7G03

What is the typical input impedance of an op-amp?

Select	Answer
A	1000 ohms
B	100 ohms
C	Very low
D	Very high

38. - E7H14

What is a phase-locked loop circuit?

Select	Answer
A	An electronic circuit consisting of a precision push-pull amplifier with a differential input
B	An electronic servo loop consisting of a phase detector, a low-pass filter, a voltage-controlled oscillator, and a stable reference oscillator
C	An electronic servo loop consisting of a ratio detector, reactance modulator, and voltage-controlled oscillator
D	An electronic circuit also known as a monostable multivibrator

39. - E8A07

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

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

40. - E8B09

What is deviation ratio?

Select	Answer
A	The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency
B	The ratio of the audio modulating frequency to the center carrier frequency
C	The ratio of the highest audio modulating frequency to the average audio modulating frequency
D	The ratio of the carrier center frequency to the audio modulating 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 minimize bandwidth
B	To improve carrier suppression
C	To simplify modulation
D	All these choices are correct

42. - E8D08

What parameter evaluates distortion of an AFSK signal caused by excessive input audio levels?

Select	Answer
A	Signal-to-noise ratio
B	Repeat Request Rate (RRR)
C	Baud rate
D	Intermodulation Distortion (IMD)

43. - E9A11

Which of the following factors determines ground losses for a ground-mounted vertical antenna operating in the 3 MHz to 30 MHz range?

Select	Answer
A	The standing wave ratio
B	Distance from the transmitter
C	Take-off angle
D	Soil conductivity

44. - E9B01

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

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

45. - E9C10

Which of the following describes a Zepp antenna?

Select	Answer
A	An omni-directional antenna commonly used for satellite communications
B	A dipole constructed from zip cord
C	A vertical array capable of quickly changing the direction of maximum radiation by changing phasing lines
D	An end-fed dipole antenna

46. - E9D07

What is an advantage of using top loading in a shortened HF vertical antenna?

Select	Answer
A	Lower Q
B	Greater structural strength
C	Higher losses
D	Improved radiation efficiency

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	75 ohms
B	62 ohms
C	450 ohms
D	50 ohms

48. - E9F06

What is the approximate physical length of an air-insulated, parallel conductor transmission line that is electrically 1/2 wavelength long at 14.10 MHz?

Select	Answer
A	7.0 meters
B	13.3 meters
C	8.5 meters
D	10.6 meters

49. - E9G10

What do the arcs on a Smith chart represent?

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

50. - E9H03

What is Receiving Directivity Factor (RDF)?

Select	Answer
A	Forward gain compared to the gain in the reverse direction
B	Relative directivity compared to isotropic
C	Forward gain compared to average gain over the entire hemisphere
D	Relative directivity compared to a dipole

Figure E6-3

Figure E9-1