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

Logging in (or registering) will help the system to select questions that you need to focus on.

1. - E0A07

How may dangerous levels of carbon monoxide from an emergency generator be detected?

Select	Answer
A	By the yellowish appearance of the gas
B	Any ordinary smoke detector can be used
C	Only with a carbon monoxide detector
D	By the odor

2. - E1A09

What action or actions should you take if your digital message forwarding station inadvertently forwards a communication that violates FCC rules?

Select	Answer
A	Notify the originating station that the communication does not comply with FCC rules
B	All these choices are correct
C	Notify the nearest FCC Field Engineers office
D	Discontinue forwarding the communication as soon as you become aware of it

3. - E1B10

What frequencies are authorized to an amateur station operating under RACES rules?

Select	Answer
A	All amateur service frequencies authorized to the control operator
B	Military Auxiliary Radio System (MARS) channels
C	Specific segments in the amateur service MF, HF, VHF and UHF bands
D	Specific local government channels

4. - E1C07

At what level below a signal's mean power level is its bandwidth determined according to FCC rules?

Select	Answer
A	3 dB
B	23 dB
C	6 dB
D	26 dB

5. - E1D06

What is the maximum permitted transmitter output power when operating a model craft by telecommand?

Select	Answer
A	5 watts
B	2 watts
C	1 watt
D	100 watts

6. - E1E06

Who is responsible for the proper conduct and necessary supervision during an amateur operator license examination session?

Select	Answer
A	Each administering VE
B	The VE session manager
C	The VEC coordinating the session
D	The FCC

7. - E1F04

Which of the following geographic descriptions approximately describes "Line A"?

Select	Answer
A	A line roughly parallel to and east of the U.S. Pacific coastline
B	A line roughly parallel to and south of the border between the U.S. and Canada
C	A line roughly parallel to and north of the border between the U.S. and Mexico
D	A line roughly parallel to and west of the U.S. Atlantic coastline

8. - E2A01

What is the direction of an ascending pass for an amateur satellite?

Select	Answer
A	From north to south
B	From west to east
C	From south to north
D	From east to west

9. - E2B12

What signals SSTV receiving software to begin a new picture line?

Select	Answer
A	Elapsed time
B	Specific tone frequencies
C	Specific tone amplitudes
D	A two-tone signal

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 your full call sign and grid square
B	Send only the last two letters of your call sign until you make contact
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	PACTOR III
B	MSK144
C	JT65
D	Olivia

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 send a constant tone code to establish a frequency for future use
C	ALE constantly scans a list of frequencies, activating the radio when the designated call sign is received
D	ALE radios monitor an internet site for the frequency they are being paged on

13. - E3A14

What is meant by circularly polarized electromagnetic waves?

Select	Answer
A	Waves with an electric field bent into a circular shape
B	Waves that circle the Earth
C	Waves with a rotating electric field
D	Waves produced by a loop antenna

14. - E3B05

Which amateur bands typically support long-path propagation?

Select	Answer
A	160 meters to 10 meters
B	Only 160 meters to 40 meters
C	Only 30 meters to 10 meters
D	6 meters to 2 meters

15. - E3C03

Which of the following signal paths is most likely to experience high levels of absorption when the A index or K index is elevated?

Select	Answer
A	Transequatorial
B	NVIS
C	Sporadic E
D	Polar

16. - E4A01

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

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

17. - E4B05

What three test loads are used to calibrate an RF vector network analyzer?

Select	Answer
A	Short circuit, open circuit, and resonant circuit
B	50 ohms, 75 ohms, and 90 ohms
C	50 ohms through 1/8 wavelength, 1/4 wavelength, and 1/2 wavelength of coaxial cable
D	Short circuit, open circuit, and 50 ohms

18. - E4C13

How does a narrow-band roofing filter affect receiver performance?

Select	Answer
A	It improves intelligibility by using low Q circuitry to reduce ringing
B	All these choices are correct
C	It improves sensitivity by reducing front end noise
D	It improves dynamic range by attenuating strong signals near the receive frequency

19. - E4D02

Which of the following describes problems caused by poor dynamic range in a receiver?

Select	Answer
A	Cross-modulation of the desired signal and insufficient audio power to operate the speaker
B	Spurious signals caused by cross-modulation and desensitization from strong adjacent signals
C	Oscillator instability and severe audio distortion of all but the strongest received signals
D	Oscillator instability requiring frequent retuning and loss of ability to recover the opposite sideband

20. - E4E02

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

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

21. - E5A07

What is the magnitude of the current at the input of a parallel RLC circuit at resonance?

Select	Answer
A	Maximum
B	R/L
C	L/R
D	Minimum

22. - E5B11

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 25 ohms, R is 100 ohms, and XL is 50 ohms?

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

23. - E5C03

Which of the following represents an inductive reactance in polar coordinates?

Select	Answer
A	A negative magnitude
B	A negative phase angle
C	A positive magnitude
D	A positive phase angle

24. - E5D13

How many watts are consumed in a circuit consisting of a 100-ohm resistor in series with a 100-ohm inductive reactance drawing 1 ampere?

Select	Answer
A	200 watts
B	70.7 watts
C	141.4 watts
D	100 watts

25. - E6A02

Which of the following semiconductor materials contains excess free electrons?

Select	Answer
A	N-type
B	Insulated gate
C	Bipolar
D	P-type

26. - E6B04

What type of semiconductor device is designed for use as a voltage-controlled capacitor?

Select	Answer
A	Varactor diode
B	Silicon-controlled rectifier
C	Tunnel diode
D	Zener diode

27. - E6C05

What is an advantage of CMOS logic devices over TTL devices?

Select	Answer
A	Lower distortion
B	Immune to damage from static discharge
C	Differential output capability
D	Lower power consumption

28. - E6D02

What is the equivalent circuit of a quartz crystal?

Select	Answer
A	Motional capacitance, motional inductance, and loss resistance in series, all in parallel with a shunt capacitor representing electrode and stray capacitance
B	Motional inductance and loss resistance in series, paralleled with motional capacitance and a capacitor representing electrode and stray capacitance
C	Motional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in series
D	Motional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in parallel

29. - E6E11

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

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

30. - E6F06

Which of these materials is most commonly used to create photoconductive devices?

Select	Answer
A	A heavy metal
B	A crystalline semiconductor
C	A liquid semiconductor
D	An ordinary metal

31. - E7A08

What logical operation does an OR gate perform?

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

32. - E7B08

How can an RF power amplifier be neutralized?

Select	Answer
A	By increasing the driving power
B	By feeding a 180-degree out-of-phase portion of the output back to the input
C	By reducing the driving power
D	By feeding an in-phase component of the output back to the input

33. - E7C05

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

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

34. - E7D13

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

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

35. - E7E10

How does a diode envelope detector function?

Select	Answer
A	By rectification and filtering of RF signals
B	By mixing signals with noise in the transition region of the diode
C	By breakdown of the Zener voltage
D	By sensing the change of reactance in the diode with respect to frequency

36. - E7F10

What aspect of receiver analog-to-digital conversion determines the maximum receive bandwidth of a Direct Digital Conversion SDR?

Select	Answer
A	Sample rate
B	Sample clock phase noise
C	Sample width in bits
D	Processor latency

37. - E7G06

What is the gain-bandwidth of an operational amplifier?

Select	Answer
A	The gain of the amplifier at a filter's cutoff frequency
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 frequency at which the amplifier's offset voltage is zero

38. - E7H03

How is positive feedback supplied in a Hartley oscillator?

Select	Answer
A	Through a neutralizing capacitor
B	Through a tapped coil
C	Through a capacitive divider
D	Through link coupling

39. - E8A09

How many different input levels can be encoded by an analog-to-digital converter with 8-bit resolution?

Select	Answer
A	256
B	256 divided by the gain of the input amplifier
C	8 multiplied by the gain of the input amplifier
D	8

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. - E8C07

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

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

42. - E8D02

What spread spectrum communications technique uses a high-speed binary bit stream to shift the phase of an RF carrier?

Select	Answer
A	Binary phase-shift keying
B	Frequency hopping
C	Phase compandored spread spectrum
D	Direct sequence

43. - E9A12

How much gain does an antenna have compared to a 1/2-wavelength dipole when it has 6 dB gain over an isotropic antenna?

Select	Answer
A	6.0 dB
B	3.85 dB
C	2.79 dB
D	8.15 dB

44. - E9B03

In the antenna radiation pattern shown in Figure E9-1, what is the front-to-side ratio?

Select	Answer
A	18 dB
B	24 dB
C	12 dB
D	14 dB

45. - E9C10

Which of the following describes a Zepp antenna?

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

46. - E9D05

What usually occurs if a Yagi antenna is designed solely for maximum forward gain?

Select	Answer
A	The front-to-back ratio increases
B	The SWR is reduced
C	The front-to-back ratio decreases
D	The frequency response is widened over the whole frequency band

47. - E9E09

Which of the following is used to shunt-feed a grounded tower at its base?

Select	Answer
A	Hairpin match
B	Gamma match
C	All these choices are correct
D	Double-bazooka match

48. - E9F10

What impedance does a 1/8-wavelength transmission line present to a generator when the line is shorted at the far end?

Select	Answer
A	A capacitive reactance
B	An inductive reactance
C	Zero
D	The same as the characteristic impedance of the line

49. - E9G05

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

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

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 E9-1