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

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1. - E0A04

When evaluating a site with multiple transmitters operating at the same time, the operators and licensees of which transmitters are responsible for mitigating over-exposure situations?

Select	Answer
A	Each transmitter operating with a duty cycle greater than 50 percent
B	Only commercial transmitters
C	Only the most powerful transmitter
D	Each transmitter that produces 5 percent or more of its MPE limit in areas where the total MPE limit is exceeded.

2. - E1A02

When using a transceiver that displays the carrier frequency of phone signals, which of the following displayed frequencies represents the lowest frequency at which a properly adjusted LSB emission will be totally within the band?

Select	Answer
A	300 Hz above the lower band edge
B	3 kHz above the lower band edge
C	1 kHz above the lower band edge
D	The exact lower band edge

3. - E1B10

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

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

4. - E1C14

How long must an operator wait after filing a notification with the Utilities Technology Council (UTC) before operating on the 2200 meter or 630 meter band?

Select	Answer
A	Operators may not operate until a test signal has been transmitted in coordination with the local power company
B	Operators may operate after 30 days, providing they have not been told that their station is within 1 km of PLC systems using those frequencies
C	Operators must not operate until approval is received
D	Operations may commence immediately, and may continue unless interference is reported by the UTC

5. - E1D04

Which of the following is required in the identification transmissions from a balloon-borne telemetry station?

Select	Answer
A	Call sign
B	All these choices are correct
C	The station's six-character Maidenhead grid locator
D	The output power of the balloon transmitter

6. - E1E12

What must the VE team do with the application form if the examinee does not pass the exam?

Select	Answer
A	Maintain the application form with the VEC's records
B	Return the application document to the examinee
C	Destroy the application form
D	Send the application form to the FCC and inform the FCC of the grade

7. - E1F06

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

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

8. - E2A06

What are Keplerian elements?

Select	Answer
A	Phase reversing elements in a Yagi antenna
B	Encrypting codes used for spread spectrum modulation
C	Parameters that define the orbit of a satellite
D	High-emission heater filaments used in magnetron tubes

9. - E2B11

What is the function of the Vertical Interval Signaling (VIS) code sent as part of an SSTV transmission?

Select	Answer
A	To provide vertical synchronization
B	To identify the SSTV mode being used
C	To identify the call sign of the station transmitting
D	To lock the color burst oscillator in color SSTV images

10. - E2C03

From which of the following bands is amateur radio contesting generally excluded?

Select	Answer
A	6 meters
B	2 meters
C	30 meters
D	33 centimeters

11. - E2D05

What is one advantage of the JT65 mode?

Select	Answer
A	Easily copied by ear if necessary
B	Uses only a 65 Hz bandwidth
C	Permits fast-scan TV transmissions over narrow bandwidth
D	The ability to decode signals which have a very low signal-to-noise ratio

12. - E2E08

Which of the following HF digital modes can be used to transfer binary files?

Select	Answer
A	AMTOR
B	RTTY
C	PACTOR
D	Hellschreiber

13. - E3A06

What might help to restore contact when DX signals become too weak to copy across an entire HF band a few hours after sunset?

Select	Answer
A	Wait 24 hours before attempting another communication on the band
B	Switch to a lower frequency HF band
C	Wait 90 minutes or so for the signal degradation to pass
D	Switch to a higher frequency HF band

14. - E3B05

Which amateur bands typically support long-path propagation?

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

15. - E3C11

What does VOACAP software model?

Select	Answer
A	VHF radio propagation
B	AC voltage and impedance
C	AC current and impedance
D	HF propagation

16. - E4A02

Which of the following parameters does a spectrum analyzer display on the vertical and horizontal axes?

Select	Answer
A	RF amplitude and frequency
B	SWR and time
C	SWR and frequency
D	RF amplitude and time

17. - E4B08

Which of the following can be used to measure the Q of a series-tuned circuit?

Select	Answer
A	The resonant frequency of the circuit
B	The inductance to capacitance ratio
C	The frequency shift
D	The bandwidth of the circuit's frequency response

18. - E4C09

Which of the following choices is a good reason for selecting a high frequency for the design of the IF in a superheterodyne HF or VHF communications receiver?

Select	Answer
A	Reduced drift
B	Easier for front-end circuitry to eliminate image responses
C	Fewer components in the receiver
D	Improved receiver noise figure

19. - E4D04

Which of the following may reduce or eliminate intermodulation interference in a repeater caused by another transmitter operating in close proximity?

Select	Answer
A	A properly terminated circulator at the output of the repeater's transmitter
B	Utilizing a Class C final amplifier
C	Utilizing a Class D final amplifier
D	A band-pass filter in the feed line between the transmitter and receiver

20. - E4E01

What problem can occur when using an automatic notch filter (ANF) to remove interfering carriers while receiving CW signals?

Select	Answer
A	Received CW signals will appear to be modulated at the DSP clock frequency
B	Removal of the CW signal as well as the interfering carrier
C	Ringing in the DSP filter will completely remove the spaces between the CW characters
D	Any nearby signal passing through the DSP system will overwhelm the desired signal

21. - E5A14

What is the resonant frequency of an RLC circuit if R is 22 ohms, L is 50 microhenries and C is 40 picofarads?

Select	Answer
A	3.56 MHz
B	1.78 MHz
C	22.36 MHz
D	44.72 MHz

22. - E5B06

What is susceptance?

Select	Answer
A	A measure of the efficiency of a transformer
B	The imaginary part of admittance
C	The ratio of magnetic field to electric field
D	The magnetic impedance of a circuit

23. - E5C02

How are impedances described in polar coordinates?

Select	Answer
A	By X and R values
B	By Y and G values
C	By real and imaginary parts
D	By phase angle and magnitude

24. - E5D05

What is the power factor of an RL circuit having a 30-degree phase angle between the voltage and the current?

Select	Answer
A	0.577
B	0.5
C	1.73
D	0.866

25. - E6A04

What is the name given to an impurity atom that adds holes to a semiconductor crystal structure?

Select	Answer
A	Donor impurity
B	N-type impurity
C	Acceptor impurity
D	Insulator impurity

26. - E6B03

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

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

27. - E6C07

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

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

28. - E6D03

Which of the following is an aspect of the piezoelectric effect?

Select	Answer
A	Generation of electrical energy in the presence of light
B	Increased conductivity in the presence of light
C	Mechanical deformation of material by the application of a magnetic field
D	Mechanical deformation of material by the application of a voltage

29. - E6E09

Which of the following component package types would be most suitable for use at frequencies above the HF range?

Select	Answer
A	Radial lead
B	Surface mount
C	Axial lead
D	TO-220

30. - E6F05

Which describes an optical shaft encoder?

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

31. - E7A05

Which of the following is a circuit that continuously alternates between two states without an external clock?

Select	Answer
A	J-K flip-flop
B	Astable multivibrator
C	T flip-flop
D	Monostable multivibrator

32. - E7B05

What can be done to prevent unwanted oscillations in an RF power amplifier?

Select	Answer
A	Tune both the input and output for maximum power
B	Tune the stage for maximum SWR
C	Install parasitic suppressors and/or neutralize the stage
D	Use a phase inverter in the output filter

33. - E7C08

Which of the following factors has the greatest effect on the bandwidth and response shape of a crystal ladder filter?

Select	Answer
A	The amplitude of the signals passing through the filter
B	The gain of the RF stage preceding the filter
C	The relative frequencies of the individual crystals
D	The DC voltage applied to the quartz crystal

34. - E7D01

How does a linear electronic voltage regulator work?

Select	Answer
A	The conduction of a control element is varied to maintain a constant output voltage
B	It has a ramp voltage as its output
C	The control element duty cycle is proportional to the line or load conditions
D	It eliminates the need for a pass transistor

35. - E7E02

What is the function of a reactance modulator?

Select	Answer
A	To produce PM signals by using an electrically variable resistance
B	To produce AM signals by using an electrically variable resistance
C	To produce PM or FM signals by using an electrically variable inductance or capacitance
D	To produce AM signals by using an electrically variable inductance or capacitance

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	Processor latency
C	Sample clock phase noise
D	Sample width in bits

37. - E7G06

What is the gain-bandwidth of an operational amplifier?

Select	Answer
A	The frequency at which the amplifier's offset voltage is zero
B	The gain of the amplifier at a filter's cutoff frequency
C	The maximum frequency for a filter circuit using that type of amplifier
D	The frequency at which the open-loop gain of the amplifier equals one

38. - E7H13

Which of the following is a technique for providing highly accurate and stable oscillators needed for microwave transmission and reception?

Select	Answer
A	Use a temperature-controlled high Q dielectric resonator
B	Use a rubidium stabilized reference oscillator
C	All these choices are correct
D	Use a GPS signal reference

39. - E8A02

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

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

40. - E8B03

What is the modulation index of an FM-phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency when the modulating frequency is 1000 Hz?

Select	Answer
A	3
B	3000
C	1000
D	0.3

41. - E8C04

What technique minimizes the bandwidth of a PSK31 signal?

Select	Answer
A	Reed-Solomon character encoding
B	Use of trapezoidal data pulses
C	Zero-sum character encoding
D	Use of sinusoidal data pulses

42. - E8D08

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

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

43. - E9A08

What is antenna bandwidth?

Select	Answer
A	Antenna length divided by the number of elements
B	The frequency range over which an antenna satisfies a performance requirement
C	The angle between the half-power radiation points
D	The angle formed between two imaginary lines drawn through the element ends

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. - E9C06

What is the effect of adding a terminating resistor to a rhombic antenna?

Select	Answer
A	It changes the radiation pattern from horizontal to vertical polarization
B	It decreases the ground loss
C	It reflects the standing waves on the antenna elements back to the transmitter
D	It changes the radiation pattern from bidirectional to unidirectional

46. - E9D11

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

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

47. - E9E10

Which of these choices is an effective way to match an antenna with a 100-ohm feed point impedance to a 50-ohm coaxial cable feed line?

Select	Answer
A	Insert a 1/4-wavelength piece of 75-ohm coaxial cable transmission line in series between the antenna terminals and the 50-ohm feed cable
B	Connect a 1/2 wavelength shorted stub of 75-ohm cable in parallel with the 50-ohm cable where it attaches to the antenna
C	Insert a 1/2 wavelength piece of 300-ohm twinlead in series between the antenna terminals and the 50-ohm feed cable
D	Connect a 1/4-wavelength open stub of 300-ohm twinlead in parallel with the coaxial feed line where it connects to the antenna

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	6.9 meters
B	8.3 meters
C	5.2 meters
D	10.4 meters

49. - E9G11

How are the wavelength scales on a Smith chart calibrated?

Select	Answer
A	In fractions of antenna electrical frequency
B	In fractions of transmission line electrical wavelength
C	In fractions of antenna electrical wavelength
D	In fractions of transmission line electrical frequency

50. - E9H08

What is the function of a sense antenna?

Select	Answer
A	It allows DF antennas to receive signals at different vertical angles
B	It increases the sensitivity of a DF antenna array
C	It modifies the pattern of a DF antenna array to provide a null in one direction
D	It provides diversity reception that cancels multipath signals

Figure E9-1