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	Ingestion of ozone gas from the cooling system
D	Blood clotting from the intense magnetic field

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	100 watts PEP effective radiated power relative to an isotropic radiator
C	50 watts PEP effective radiated power relative to an isotropic radiator
D	50 watts PEP effective radiated power relative to a dipole

3. - E1B06

Which of the following additional rules apply if you are installing an amateur station antenna at a site at or near a public use airport?

Select	Answer
A	You must file an Environmental Impact Statement with the EPA before construction begins
B	You must obtain a construction permit from the airport zoning authority
C	You may have to notify the Federal Aviation Administration and register it with the FCC as required by Part 17 of the FCC rules
D	You must submit engineering drawings to the FAA

4. - E1C13

What notifications must be given before transmitting on the 630 meter or 2200 meter bands?

Select	Answer
A	An environmental impact statement must be filed with the Department of the Interior
B	Operators must inform the Utilities Technology Council (UTC) of their call sign and coordinates of the station
C	Operators must inform the FAA of their intent to operate, giving their call sign and distance to the nearest runway
D	A special endorsement must be requested from the FCC

5. - E1D01

What is the definition of telemetry?

Select	Answer
A	One-way transmission that initiates, modifies, or terminates the functions of a device at a distance
B	One-way transmission of measurements at a distance from the measuring instrument
C	Two-way transmissions of data
D	Two-way transmissions in excess of 1000 feet

6. - E1E04

Which of the following best describes the Volunteer Examiner accreditation process?

Select	Answer
A	The amateur operator applying must pass a VE examination administered by the FCC Enforcement Bureau
B	The procedure by which a VEC confirms that the VE applicant meets FCC requirements to serve as an examiner
C	The prospective VE obtains accreditation from the FCC
D	Each General, Advanced and Amateur Extra Class operator is automatically accredited as a VE when the license is granted

7. - E1F03

Under what circumstances may a dealer sell an external RF power amplifier capable of operation below 144 MHz if it has not been granted FCC certification?

Select	Answer
A	The equipment dealer assembled it from a kit
B	It was imported from a manufacturer in another country and was certificated by that country's government
C	It was purchased in used condition from an amateur operator and is sold to another amateur operator for use at that operator's station
D	It was imported from a manufacturer in a country that does not require certification of RF power amplifiers

8. - E2A08

Why should effective radiated power to a satellite that uses a linear transponder be limited?

Select	Answer
A	To avoid reducing the downlink power to all other users
B	To prevent the satellite from emitting out-of-band signals
C	To prevent creating errors in the satellite telemetry
D	To avoid interfering with terrestrial QSOs

9. - E2B06

What is vestigial sideband modulation?

Select	Answer
A	Spread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation
B	Narrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier
C	Amplitude modulation in which one complete sideband and a portion of the other are transmitted
D	A type of modulation in which one sideband is inverted

10. - E2C11

How should you generally identify your station when attempting to contact a DX station during a contest or in a pileup?

Select	Answer
A	Send only the last two letters of your call sign until you make contact
B	Send your full call sign and grid square
C	Send your full call sign once or twice
D	Send the call sign of the DX station three times, the words this is,then your call sign three times

11. - E2D03

Which of the following digital modes is especially useful for EME communications?

Select	Answer
A	JT65
B	PACTOR III
C	Olivia
D	MSK144

12. - E2E05

Which of these digital modes does not support keyboard-to-keyboard operation?

Select	Answer
A	PSK31
B	PACTOR
C	MFSK
D	RTTY

13. - E3A08

When a meteor strikes the Earth's atmosphere, a cylindrical region of free electrons is formed at what layer of the ionosphere?

Select	Answer
A	The F2 layer
B	The E layer
C	The F1 layer
D	The D layer

14. - E3B09

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

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

15. - E3C12

How does the maximum range of ground-wave propagation change when the signal frequency is increased?

Select	Answer
A	It increases
B	It decreases
C	It peaks at roughly 14 MHz
D	It stays the same

16. - E4A09

Which of the following is good practice when using an oscilloscope probe?

Select	Answer
A	All these choices are correct
B	Keep the signal ground connection of the probe as short as possible
C	Never use a high-impedance probe to measure a low-impedance circuit
D	Never use a DC-coupled probe to measure an AC circuit

17. - E4B07

What do the subscripts of S parameters represent?

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

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	13.845 MHz
B	14.755 MHz
C	14.445 MHz
D	15.210 MHz

19. - E4D09

What is the purpose of the preselector in a communications receiver?

Select	Answer
A	To increase rejection of signals outside the desired band
B	To store often-used frequencies
C	To provide a range of AGC time constants
D	To allow selection of the optimum RF amplifier device

20. - E4E02

Which of the following types of noise can often be reduced with a digital signal processing noise filter?

Select	Answer
A	Broadband white noise
B	All these choices are correct
C	Power line noise
D	Ignition noise

21. - E5A13

What is an effect of increasing Q in a series resonant circuit?

Select	Answer
A	Internal voltages increase
B	Phase shift can become uncontrolled
C	Parasitic effects are minimized
D	Fewer components are needed for the same performance

22. - E5B08

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 100 ohms, R is 100 ohms, and XL is 75 ohms?

Select	Answer
A	76 degrees with the voltage lagging the current
B	14 degrees with the voltage leading the current
C	76 degrees with the voltage leading the current
D	14 degrees with the voltage lagging the current

23. - E5C12

Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and a 19-picofarad capacitor at 21.200 MHz?

Select	Answer
A	Point 7
B	Point 8
C	Point 1
D	Point 3

24. - E5D11

What is the power factor of an RL circuit having a 60-degree phase angle between the voltage and the current?

Select	Answer
A	1.73
B	1.414
C	0.5
D	0.866

25. - E6A06

What is the beta of a bipolar junction transistor?

Select	Answer
A	The frequency at which the current gain is reduced to 0.707
B	The breakdown voltage of the base to collector junction
C	The change in collector current with respect to base current
D	The switching speed

26. - E6B10

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

Select	Answer
A	1
B	6
C	5
D	7

27. - E6C07

What best describes a pull-up or pull-down resistor?

Select	Answer
A	A resistor in a keying circuit used to reduce key clicks
B	A resistor connected to the positive or negative supply line used to establish a voltage when an input or output is an open circuit
C	A resistor connected to an op-amp output that prevents signals from exceeding the power supply voltage
D	A resistor that ensures that an oscillator frequency does not drift

28. - E6D10

What is a primary advantage of using a toroidal core instead of a solenoidal core in an inductor?

Select	Answer
A	Toroidal cores confine most of the magnetic field within the core material
B	Toroidal cores make it easier to couple the magnetic energy into other components
C	Toroidal cores have lower Q characteristics
D	Toroidal cores exhibit greater hysteresis

29. - E6E11

What is a characteristic of DIP packaging used for integrated circuits?

Select	Answer
A	Package mounts in a direct inverted position
B	Two chips in each package (Dual In Package)
C	Low leakage doubly insulated package
D	A total of two rows of connecting pins placed on opposite sides of the package (Dual In-line Package)

30. - E6F07

What is a solid-state relay?

Select	Answer
A	A mechanical relay that latches in the on or off state each time it is pulsed
B	A relay using transistors to drive the relay coil
C	A semiconductor passive delay line
D	A device that uses semiconductors to implement the functions of an electromechanical relay

31. - E7A08

What logical operation does an OR gate perform?

Select	Answer
A	It produces logic 1 at its output if any or all inputs are logic 1
B	It only produces logic 0 at its output when all inputs are logic 1
C	It produces logic 0 at its output if all inputs are logic 1
D	It produces logic 1 at its output if all inputs are logic 0

32. - E7B07

Which of the following is a likely result when a Class C amplifier is used to amplify a single-sideband phone signal?

Select	Answer
A	Signal distortion and excessive bandwidth
B	Reduced intermodulation products
C	Signal inversion
D	Increased overall intelligibility

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

34. - E7D03

What device is typically used as a stable voltage reference in a linear voltage regulator?

Select	Answer
A	A varactor diode
B	An SCR
C	A tunnel diode
D	A Zener diode

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. - E7F04

What is a common method of generating an SSB signal using digital signal processing?

Select	Answer
A	Signals are combined in quadrature phase relationship
B	Mixing products are converted to voltages and subtracted by adder circuits
C	Varying quartz crystal characteristics emulated in digital form
D	A frequency synthesizer removes the unwanted sidebands

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. - E7H06

Which of the following oscillator circuits are commonly used in VFOs?

Select	Answer
A	Negative feedback and balanced feedback
B	Pierce and Zener
C	Colpitts and Hartley
D	Armstrong and deForest

39. - E8A02

Which of the following is a type of analog-to-digital conversion?

Select	Answer
A	Phase reversal
B	Successive approximation
C	Level shifting
D	Harmonic regeneration

40. - E8B04

What is the modulation index of an FM-phone signal having a maximum carrier deviation of plus or minus 6 kHz when modulated with a 2 kHz modulating frequency?

Select	Answer
A	2000
B	3
C	6000
D	1/3

41. - E8C10

How may data rate be increased without increasing bandwidth?

Select	Answer
A	Using forward error correction
B	Increasing analog-to-digital conversion resolution
C	Using a more efficient digital code
D	It is impossible

42. - E8D05

What is the most common method of reducing key clicks?

Select	Answer
A	High-pass filters at the transmitter output
B	Low-pass filters at the transmitter output
C	Increase keying waveform rise and fall times
D	Reduce keying waveform rise and fall times

43. - E9A01

What is an isotropic antenna?

Select	Answer
A	A spacecraft antenna used to direct signals toward Earth
B	A theoretical, omnidirectional antenna used as a reference for antenna gain
C	A grounded antenna used to measure Earth conductivity
D	A horizontally polarized antenna used to compare Yagi antennas

44. - E9B09

What type of computer program technique is commonly used for modeling antennas?

Select	Answer
A	Method of Moments
B	Mutual impedance analysis
C	Calculus differentiation with respect to physical properties
D	Graphical analysis

45. - E9C04

What happens to the radiation pattern of an unterminated long wire antenna as the wire length is increased?

Select	Answer
A	The lobes align more in the direction of the wire
B	The lobes become more perpendicular to the wire
C	The front-to-back ratio decreases
D	The vertical angle increases

46. - E9D04

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

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

47. - E9E05

How must an antenna's driven element be tuned to use a hairpin matching system?

Select	Answer
A	The driven element resonance must be lower than the operating frequency
B	The driven element radiation resistance must be higher than the characteristic impedance of the transmission line
C	The driven element reactance must be capacitive
D	The driven element reactance must be inductive

48. - E9F09

What is the approximate physical length of a foam polyethylene dielectric coaxial transmission line that is electrically 1/4 wavelength long at 7.2 MHz?

Select	Answer
A	5.2 meters
B	8.3 meters
C	6.9 meters
D	10.4 meters

49. - E9G04

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

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

50. - E9H07

Why is RF attenuation used when direction-finding?

Select	Answer
A	To increase receiver sensitivity
B	To compensate for isotropic directivity and the antenna effect of feed lines
C	To narrow the receiver bandwidth
D	To prevent receiver overload which reduces pattern nulls

Figure E5-1

Figure E6-2

Figure E7-3