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

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1. - E0A08

What does SAR measure?

Select	Answer
A	Synthetic Aperture Ratio of the human body
B	Signal Amplification Rating
C	The rate at which RF energy is absorbed by the body
D	The rate of RF energy reflected from stationary terrain

2. - E1A12

What special operating frequency restrictions are imposed on slow scan TV transmissions?

Select	Answer
A	They are restricted to 7.245 MHz, 14.245 MHz, 21.345 MHz, and 28.945 MHz
B	They are not permitted above 54 MHz
C	They are restricted to phone band segments
D	None; they are allowed on all amateur frequencies

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	An amateur station transmission made without the proper call sign identification
C	A signal transmitted to prevent its detection by any station other than the intended recipient
D	Any transmitted signal that unintentionally interferes with another licensed radio station

4. - E1C03

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

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

5. - E1D11

Which amateur stations are eligible to operate as Earth stations?

Select	Answer
A	Any amateur station whose licensee has filed a pre-space notification with the FCC's International Bureau
B	Any amateur station, subject to the privileges of the class of operator license held by the control operator
C	Only those of Amateur Extra Class operators
D	Only those of General, Advanced or Amateur Extra Class operators

6. - E1E08

To which of the following examinees may a VE not administer an examination?

Select	Answer
A	Employees of the VE
B	Relatives of the VE as listed in the FCC rules
C	All these choices are correct
D	Friends of the VE

7. - E1F06

Under what circumstances might the FCC issue a Special Temporary Authority (STA) to an amateur station?

Select	Answer
A	To provide additional spectrum for personal use
B	To provide temporary operation while awaiting normal licensing
C	To allow regular operation on Land Mobile channels
D	To provide for experimental amateur communications

8. - E2A13

Which of the following techniques is normally used by low Earth orbiting digital satellites to relay messages around the world?

Select	Answer
A	Digipeating
B	Node hopping
C	Store-and-forward
D	Multi-satellite relaying

9. - E2B10

What aspect of an analog slow-scan television signal encodes the brightness of the picture?

Select	Answer
A	Tone frequency
B	Tone amplitude
C	Sync amplitude
D	Sync frequency

10. - E2C10

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

Select	Answer
A	All these choices are correct
B	Because the DX station may be transmitting on a frequency that is prohibited to some responding stations
C	To separate the calling stations from the DX station
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	Latitude and longitude
B	Polar coordinates
C	Radio direction finding spectrum analysis
D	Time and frequency

12. - E2E11

What is the difference between direct FSK and audio FSK?

Select	Answer
A	Only direct FSK can be decoded by computer
B	Direct FSK occupies less bandwidth
C	Direct FSK applies the data signal to the transmitter VFO, while AFSK transmits tones via phone
D	Direct FSK can transmit faster baud rates

13. - E3A11

What is a typical range for tropospheric propagation of microwave signals?

Select	Answer
A	10 miles to 50 miles
B	1200 miles
C	100 miles to 300 miles
D	2500 miles

14. - E3B09

At what time of year is sporadic E propagation most likely to occur?

Select	Answer
A	Around the solstices, especially the winter solstice
B	Around the equinoxes, especially the fall equinox
C	Around the solstices, especially the summer solstice
D	Around the equinoxes, especially the spring equinox

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	Westward
B	Eastward
C	Northward
D	Southward

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

18. - E4C02

Which of the following receiver circuits can be effective in eliminating interference from strong out-of-band signals?

Select	Answer
A	A front-end filter or pre-selector
B	A notch filter
C	A properly adjusted product detector
D	A narrow IF filter

19. - E4D08

What causes intermodulation in an electronic circuit?

Select	Answer
A	Lack of neutralization
B	Positive feedback
C	Too little gain
D	Nonlinear circuits or devices

20. - E4E11

What could cause local AM broadcast band signals to combine to generate spurious signals in the MF or HF bands?

Select	Answer
A	Nearby corroded metal joints are mixing and re-radiating the broadcast signals
B	One or more of the broadcast stations is transmitting an over-modulated signal
C	Your station receiver IF amplifier stage is defective
D	You are receiving skywave signals from a distant station

21. - E5A10

How is the Q of an RLC series resonant circuit calculated?

Select	Answer
A	Reactance of either the inductance or capacitance multiplied by the resistance
B	Reactance of either the inductance or capacitance divided by the resistance
C	Reactance of the inductance multiplied by the reactance of the capacitance
D	Resistance divided by the reactance of either the inductance or capacitance

22. - E5B12

What is admittance?

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

23. - E5C01

Which of the following represents capacitive reactance in rectangular notation?

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

24. - E5D03

What is microstrip?

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

25. - E6A12

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

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

26. - E6B10

In Figure E6-2, what is the schematic symbol for a light-emitting diode?

Select	Answer
A	6
B	7
C	5
D	1

27. - E6C09

What is a Programmable Logic Device (PLD)?

Select	Answer
A	A logic circuit that can be modified during use
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 type of transistor whose gain can be changed by digital logic circuits

28. - E6D05

What is one reason for using ferrite cores rather than powdered iron in an inductor?

Select	Answer
A	Ferrite toroids generally require fewer turns to produce a given inductance value
B	Ferrite toroids are easier to use with surface mount technology
C	Ferrite toroids generally have lower initial permeability
D	Ferrite toroids generally have better temperature stability

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	Excessive lead length
C	Too many pins
D	Epoxy coating is conductive above 300 MHz

30. - E6F02

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

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

31. - E7A11

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

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

32. - E7B04

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

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

33. - E7C04

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

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

34. - E7D10

What is the primary reason that a high-frequency switching type high-voltage power supply can be both less expensive and lighter in weight than a conventional power supply?

Select	Answer
A	The inverter design does not require any output filtering
B	It uses a diode bridge rectifier for increased output
C	It uses a large power factor compensation capacitor to recover power from the unused portion of the AC cycle
D	The high frequency inverter design uses much smaller transformers and filter components for an equivalent power output

35. - E7E01

Which of the following can be used to generate FM phone emissions?

Select	Answer
A	A balanced modulator on the oscillator
B	A reactance modulator on the final amplifier
C	A reactance modulator on the oscillator
D	A balanced modulator on the audio amplifier

36. - E7F02

What kind of digital signal processing audio filter is used to remove unwanted noise from a received SSB signal?

Select	Answer
A	A Hilbert-transform filter
B	A crystal-lattice filter
C	An adaptive filter
D	A phase-inverting filter

37. - E7G08

How does the gain of an ideal operational amplifier vary with frequency?

Select	Answer
A	It increases linearly with increasing frequency
B	It does not vary with frequency
C	It decreases linearly with increasing frequency
D	It decreases logarithmically with increasing frequency

38. - E7H09

What type of frequency synthesizer circuit uses a phase accumulator, lookup table, digital to analog converter, and a low-pass anti-alias filter?

Select	Answer
A	A phase-locked loop synthesizer
B	A diode-switching matrix synthesizer
C	A hybrid synthesizer
D	A direct digital synthesizer

39. - E8A10

What is the purpose of a low-pass filter used in conjunction with a digital-to-analog converter?

Select	Answer
A	Remove harmonics from the output caused by the discrete analog levels generated
B	Improve accuracy by removing out-of-sequence codes from the input
C	Lower the input bandwidth to increase the effective resolution
D	All these choices are correct

40. - E8B02

How does the modulation index of a phase-modulated emission vary with RF carrier frequency?

Select	Answer
A	It decreases as the RF carrier frequency increases
B	It does not depend on the RF carrier frequency
C	It increases as the RF carrier frequency increases
D	It varies with the square root of the RF carrier frequency

41. - E8C07

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

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

42. - E8D09

What is considered an acceptable maximum IMD level for an idling PSK signal?

Select	Answer
A	+15 dB
B	+10 dB
C	-30 dB
D	-20 dB

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	Take-off angle
C	Distance from the transmitter
D	Soil conductivity

44. - E9B01

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

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

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 increases in the uphill direction
D	The horizontal beamwidth decreases in the downhill direction

46. - E9D03

Where should a high Q loading coil be placed to minimize losses in a shortened vertical antenna?

Select	Answer
A	At a voltage node
B	As close to the transmitter as possible
C	As low as possible on the vertical radiator
D	Near the center of the vertical radiator

47. - E9E07

What parameter describes the interactions at the load end of a mismatched transmission line?

Select	Answer
A	Dielectric constant
B	Characteristic impedance
C	Velocity factor
D	Reflection coefficient

48. - E9F01

What is the velocity factor of a transmission line?

Select	Answer
A	The index of shielding for coaxial cable
B	The ratio of the characteristic impedance of the line to the terminating impedance
C	The velocity of the wave in the transmission line divided by the velocity of light in a vacuum
D	The velocity of the wave in the transmission line multiplied by the velocity of light in a vacuum

49. - E9G02

What type of coordinate system is used in a Smith chart?

Select	Answer
A	Voltage circles and current arcs
B	Voltage lines and current chords
C	Resistance lines and reactance chords
D	Resistance circles and reactance arcs

50. - E9H09

What is a Pennant antenna?

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

Figure E6-2

Figure E9-1