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

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

3. - E1B12

What must the control operator of a repeater operating in the 70 cm band do if a radiolocation system experiences interference from that repeater?

Select	Answer
A	Reduce the repeater antenna HAAT (Height Above Average Terrain)
B	File an FAA NOTAM (Notice to Airmen) with the repeater system's ERP, call sign, and six-character grid locator
C	All these choices are correct
D	Cease operation or make changes to the repeater to mitigate the interference

4. - E1C01

What is the maximum bandwidth for a data emission on 60 meters?

Select	Answer
A	1.5 kHz
B	60 Hz
C	2.8 kHz
D	170 Hz

5. - E1D12

Which of the following amateur stations may transmit one-way communications?

Select	Answer
A	All these choices are correct
B	A message forwarding station or automatically controlled digital station
C	A local repeater or linked repeater station
D	A space station, beacon station, or telecommand station

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	Friends of the VE
D	All these choices are correct

7. - E1F10

Who may be the control operator of an auxiliary station?

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

8. - E2A09

What do the terms L band and S band specify regarding satellite communications?

Select	Answer
A	FM and Digital Store-and-Forward systems
B	The 2 meter and 70 centimeter bands
C	Which sideband to use
D	The 23 centimeter and 13 centimeter bands

9. - E2B06

What is vestigial sideband modulation?

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

10. - E2C05

What is the function of a DX QSL Manager?

Select	Answer
A	To allocate frequencies for DXpeditions
B	To relay calls to and from a DX station
C	To handle the receiving and sending of confirmation cards for a DX station
D	To run a net to allow many stations to contact a rare DX station

11. - E2D02

Which of the following is a good technique for making meteor scatter contacts?

Select	Answer
A	Short transmissions with rapidly repeated call signs and signal reports
B	All these choices are correct
C	15-second timed transmission sequences with stations alternating based on location
D	Use of special digital modes

12. - E2E06

What is the most common data rate used for HF packet?

Select	Answer
A	1200 baud
B	110 baud
C	300 baud
D	48 baud

13. - E3A13

Which of these emission modes is best for auroral propagation?

Select	Answer
A	CW
B	SSB
C	RTTY
D	FM

14. - E3B02

What is the approximate maximum range for signals using transequatorial propagation?

Select	Answer
A	7500 miles
B	1000 miles
C	5000 miles
D	2500 miles

15. - E3C02

What is indicated by a rising A or K index?

Select	Answer
A	Decreasing disruption of the geomagnetic field
B	Higher levels of solar UV radiation
C	An increase in the critical frequency
D	Increasing disruption of the geomagnetic field

16. - E4A01

Which of the following limits the highest frequency signal that can be accurately displayed on a digital oscilloscope?

Select	Answer
A	Q of the circuit
B	Amount of memory
C	Sampling rate of the analog-to-digital converter
D	All these choices are correct

17. - E4B02

What is the significance of voltmeter sensitivity expressed in ohms per volt?

Select	Answer
A	The full scale reading of the voltmeter multiplied by its ohms per volt rating will indicate the input impedance of the voltmeter
B	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
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	When used as an ammeter, the full scale reading in amps divided by ohms per volt rating will determine the size of shunt needed

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	15.210 MHz
B	13.845 MHz
C	14.755 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	Squelch gain rollback
B	Quieting
C	Cross-modulation interference
D	Desensitization

20. - E4E02

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

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

21. - E5A12

What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 3.7 MHz and a Q of 118?

Select	Answer
A	218.3 kHz
B	31.4 kHz
C	436.6 kHz
D	15.7 kHz

22. - E5B09

What is the relationship between the AC current through a capacitor and the voltage across a capacitor?

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

23. - E5C08

What coordinate system is often used to display the phase angle of a circuit containing resistance, inductive and/or capacitive reactance?

Select	Answer
A	Elliptical coordinates
B	Polar coordinates
C	Maidenhead grid
D	Faraday grid

24. - E5D01

What is the result of skin effect?

Select	Answer
A	Thermal effects on the surface of the conductor decrease the impedance
B	As frequency decreases, RF current flows in a thinner layer of the conductor, closer to the surface
C	Thermal effects on the surface of the conductor increase the impedance
D	As frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface

25. - E6A07

Which of the following indicates that a silicon NPN junction transistor is biased on?

Select	Answer
A	Base-to-emitter resistance of approximately 6 to 7 ohms
B	Base-to-emitter voltage of approximately 0.6 to 0.7 volts
C	Base-to-emitter voltage of approximately 6 to 7 volts
D	Base-to-emitter resistance of approximately 0.6 to 0.7 ohms

26. - E6B03

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

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

27. - E6C08

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

Select	Answer
A	1
B	4
C	3
D	2

28. - E6D08

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

Select	Answer
A	Powdered-iron cores use smaller diameter wire for the same inductance
B	Powdered-iron cores generally maintain their characteristics at higher currents
C	Powdered-iron cores generally require fewer turns to produce a given inductance
D	Powdered-iron cores generally have greater initial permeability

29. - E6E04

Which is the most common input and output impedance of circuits that use MMICs?

Select	Answer
A	50 ohms
B	10 ohms
C	450 ohms
D	300 ohms

30. - E6F04

What is the photovoltaic effect?

Select	Answer
A	The conversion of electrical energy to mechanical energy
B	The conversion of light to electrical energy
C	The conversion of voltage to current when exposed to light
D	The tendency of a battery to discharge when exposed to light

31. - E7A11

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

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

32. - E7B15

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

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

33. - E7C12

What is one advantage of a Pi-matching network over an L-matching network consisting of a single inductor and a single capacitor?

Select	Answer
A	The Q of Pi-networks can be controlled
B	L-networks cannot perform impedance transformation
C	Pi-networks are more stable
D	Pi-networks provide balanced input and output

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	Input voltage multiplied by input current
C	Voltage difference from input to output multiplied by output current
D	Output voltage multiplied by output current

35. - E7E03

What is a frequency discriminator stage in a FM receiver?

Select	Answer
A	A circuit for filtering two closely adjacent signals
B	A circuit for detecting FM signals
C	An automatic band-switching circuit
D	An FM generator circuit

36. - E7F05

How frequently must an analog signal be sampled by an analog-to-digital converter so that the signal can be accurately reproduced?

Select	Answer
A	At four times the rate of the highest frequency component of the signal
B	At least half the rate of the highest frequency component of the signal
C	At least twice the rate of the highest frequency component of the signal
D	At the same rate as the highest frequency component of the signal

37. - E7G07

What magnitude of voltage gain can be expected from the circuit in Figure E73 when R1 is 10 ohms and RF is 470 ohms?

Select	Answer
A	47
B	0.21
C	24
D	94

38. - E7H15

Which of these functions can be performed by a phase-locked loop?

Select	Answer
A	Comparison of two digital input signals, digital pulse counter
B	Photovoltaic conversion, optical coupling
C	Frequency synthesis, FM demodulation
D	Wide-band AF and RF power amplification

39. - E8A10

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

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

40. - E8B11

What is digital time division multiplexing?

Select	Answer
A	Two or more signals are quadrature modulated to increase bandwidth efficiency
B	Two or more signals are arranged to share discrete time slots of a data transmission
C	Two or more data streams are assigned to discrete sub-carriers on an FM transmitter
D	Two or more data streams share the same channel by transmitting time of transmission as the sub-carrier

41. - E8C05

What is the approximate bandwidth of a 13-WPM International Morse Code transmission?

Select	Answer
A	26 Hz
B	52 Hz
C	104 Hz
D	13 Hz

42. - E8D11

What is one advantage of using ASCII code for data communications?

Select	Answer
A	It uses one character as a shift code to send numeric and special characters
B	It contains fewer information bits per character than any other code
C	It is possible to transmit both upper and lower case text
D	It includes built-in error correction features

43. - E9A06

What is the effective radiated power relative to a dipole of a repeater station with 200 watts transmitter power output, 4 dB feed line loss, 3.2 dB duplexer loss, 0.8 dB circulator loss, and 10 dBd antenna gain?

Select	Answer
A	126 watts
B	2000 watts
C	317 watts
D	300 watts

44. - E9B05

What type of antenna pattern is shown in Figure E9-2?

Select	Answer
A	Elevation
B	Azimuth
C	Radiation resistance
D	Polarization

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 horizontal beamwidth decreases 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 main lobe takeoff angle increases in the downhill direction

46. - E9D11

Which of the following conductors would be best for minimizing losses in a station's RF ground system?

Select	Answer
A	Wide flat copper strap
B	Resistive wire, such as spark plug wire
C	Stranded wire
D	Solid wire

47. - E9E01

What system matches a higher-impedance transmission line to a lower-impedance antenna by connecting the line to the driven element in two places spaced a fraction of a wavelength each side of element center?

Select	Answer
A	The gamma matching system
B	The stub matching system
C	The omega matching system
D	The delta matching system

48. - E9F07

How does ladder line compare to small-diameter coaxial cable such as RG-58 at 50 MHz?

Select	Answer
A	Lower velocity factor
B	Smaller reflection coefficient
C	Lower loss
D	Higher SWR

49. - E9G05

Which of the following is a common use for a Smith chart?

Select	Answer
A	Determine the length and position of an impedance matching stub
B	Determine the impedance of a transmission line, given the physical dimensions
C	Determine the loss/100 feet of a transmission line, given the velocity factor and conductor materials
D	Determine the gain of an antenna given the physical and electrical parameters

50. - E9H09

What is a Pennant antenna?

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

Figure E6-3

Figure E9-2