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

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1. - E0A08

What does SAR measure?

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

2. - E1A13

Who must be in physical control of the station apparatus of an amateur station aboard any vessel or craft that is documented or registered in the United States?

Select	Answer
A	Any person named in an amateur station license grant or a person holding an unrestricted Radiotelephone Operator Permit
B	Any person holding an FCC issued amateur license or who is authorized for alien reciprocal operation
C	Only a person named in an amateur station license grant
D	Only a person with an FCC Marine Radio license grant

3. - E1B04

What must be done before placing an amateur station within an officially designated wilderness area or wildlife preserve, or an area listed in the National Register of Historic Places?

Select	Answer
A	A form FSD-15 must be submitted to the Department of the Interior
B	A letter of intent must be filed with the Environmental Protection Agency
C	An Environmental Assessment must be submitted to the FCC
D	A proposal must be submitted to the National Park Service

4. - E1C04

What is meant by IARP?

Select	Answer
A	An international amateur radio permit that allows U.S. amateurs to operate in certain countries of the Americas
B	A forecast of intermittent aurora radio propagation
C	The internal amateur radio practices policy of the FCC
D	An indication of increased antenna reflected power

5. - E1D06

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

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

6. - E1E11

What must the VE team do if an examinee scores a passing grade on all examination elements needed for an upgrade or new license?

Select	Answer
A	Photocopy all examination documents and forward them to the FCC for processing
B	Issue the examinee the new or upgrade license
C	Three VEs must certify that the examinee is qualified for the license grant and that they have complied with the administering VE requirements
D	All these choices are correct

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

8. - E2A03

How is the signal inverted by an inverting linear transponder?

Select	Answer
A	The signal is detected and remodulated on the reverse sideband
B	The signal is passed through a non-linear filter
C	The signal is reduced to I and Q components and the Q component is filtered out
D	The signal is passed through a mixer and the difference rather than the sum is transmitted

9. - E2B05

Which of the following describes the use of vestigial sideband in analog fast-scan TV transmissions?

Select	Answer
A	The vestigial sideband carries the audio information
B	Vestigial sideband provides high frequency emphasis to sharpen the picture
C	The vestigial sideband contains chroma information
D	Vestigial sideband reduces bandwidth while allowing for simple video detector circuitry

10. - E2C10

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

Select	Answer
A	To separate the calling stations from the DX station
B	To improve operating efficiency by reducing interference
C	Because the DX station may be transmitting on a frequency that is prohibited to some responding stations
D	All these choices are correct

11. - E2D02

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

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

12. - E2E07

Which of the following is a possible reason that attempts to initiate contact with a digital station on a clear frequency are unsuccessful?

Select	Answer
A	Another station you are unable to hear is using the frequency
B	The protocol version you are using is not supported by the digital station
C	Your transmit frequency is incorrect
D	All these choices are correct

13. - E3A11

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

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

14. - E3B10

Why is chordal hop propagation desirable?

Select	Answer
A	Signals travel faster along ionospheric chords
B	Atmospheric noise is lower in the direction of chordal hop propagation
C	The signal experiences less loss compared to multi-hop using Earth as a reflector
D	The MUF for chordal hop propagation is much lower than for normal skip propagation

15. - E3C02

What is indicated by a rising A or K index?

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

16. - E4A08

Which of the following measures SWR?

Select	Answer
A	An ohmmeter
B	A Q meter
C	An antenna analyzer
D	A spectrum analyzer

17. - E4B03

Which S parameter is equivalent to forward gain?

Select	Answer
A	S21
B	S11
C	S12
D	S22

18. - E4C11

Why can an attenuator be used to reduce receiver overload on the lower frequency HF bands with little or no impact on signal-to-noise ratio?

Select	Answer
A	Signals are attenuated separately from the noise
B	Atmospheric noise is generally greater than internally generated noise even after attenuation
C	The attenuator has a noise filter to suppress interference
D	The attenuator has a low-pass filter to increase the strength of lower frequency signals

19. - E4D10

What does a third-order intercept level of 40 dBm mean with respect to receiver performance?

Select	Answer
A	Signals less than 40 dBm will not generate audible third-order intermodulation products
B	The receiver can tolerate signals up to 40 dB above the noise floor without producing third-order intermodulation products
C	A pair of 1 mW input signals will produce a third-order intermodulation product that is 40 dB stronger than the input signal
D	A pair of 40 dBm input signals will theoretically generate a third-order intermodulation product that has the same output amplitude as either of the input signals

20. - E4E06

What is one type of electrical interference that might be caused by a nearby personal computer?

Select	Answer
A	The appearance of unstable modulated or unmodulated signals at specific frequencies
B	A clicking noise at intervals of a few seconds
C	A whining type noise that continually pulses off and on
D	A loud AC hum in the audio output of your station receiver

21. - E5A04

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

Select	Answer
A	Approximately equal to inductive reactance
B	Low compared to the circuit resistance
C	High compared to the circuit resistance
D	Approximately equal to circuit resistance

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

23. - E5C01

Which of the following represents capacitive reactance in rectangular notation?

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

24. - E5D10

How can the true power be determined in an AC circuit where the voltage and current are out of phase?

Select	Answer
A	By dividing the apparent power by the power factor
B	By multiplying the apparent power by the power factor
C	By dividing the reactive power by the power factor
D	By multiplying the reactive power by the power factor

25. - E6A12

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

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

26. - E6B06

Which of the following is a common use of a Schottky diode?

Select	Answer
A	As a constant voltage reference in a power supply
B	As a variable capacitance in an automatic frequency control circuit
C	As a VHF/UHF mixer or detector
D	As a rectifier in high current power supplies

27. - E6C02

What happens when the level of a comparator's input signal crosses the threshold?

Select	Answer
A	The comparator enters latch-up
B	The comparator changes its output state
C	The IC input can be damaged
D	The feedback loop becomes unstable

28. - E6D02

What is the equivalent circuit of a quartz crystal?

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

29. - E6E04

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

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

30. - E6F05

Which describes an optical shaft encoder?

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

31. - E7A01

Which circuit is bistable?

Select	Answer
A	A flip-flop
B	A bipolar amplifier
C	An AND gate
D	An OR gate

32. - E7B10

In Figure E7-1, what is the purpose of R1 and R2?

Select	Answer
A	Load resistors
B	Self bias
C	Feedback
D	Voltage divider bias

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

34. - E7D07

What is the purpose of C2 in the circuit shown in Figure E7-2?

Select	Answer
A	It is a brute force filter for the output
B	To provide fixed DC bias for Q1
C	It bypasses rectifier output ripple around D1
D	To self-resonate at the hum frequency

35. - E7E10

How does a diode envelope detector function?

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

36. - E7F06

What is the minimum number of bits required for an analog-to-digital converter to sample a signal with a range of 1 volt at a resolution of 1 millivolt?

Select	Answer
A	6 bits
B	8 bits
C	10 bits
D	4 bits

37. - E7G11

What absolute voltage gain can be expected from the circuit in Figure E7-3 when R1 is 3300 ohms and RF is 47 kilohms?

Select	Answer
A	0.07
B	14
C	28
D	7

38. - E7H10

What information is contained in the lookup table of a direct digital synthesizer (DDS)?

Select	Answer
A	Frequently used receiver and transmitter frequencies
B	The phase relationship between a reference oscillator and the output waveform
C	The phase relationship between a voltage-controlled oscillator and the output waveform
D	Amplitude values that represent the desired waveform

39. - E8A08

Why would a direct or flash conversion analog-to-digital converter be useful for a software defined radio?

Select	Answer
A	Very low power consumption decreases frequency drift
B	Immunity to out-of-sequence coding reduces spurious responses
C	All these choices are correct
D	Very high speed allows digitizing high frequencies

40. - E8B02

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

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

41. - E8C11

What is the relationship between symbol rate and baud?

Select	Answer
A	Symbol rate is only used for packet-based modes
B	Baud is only used for RTTY
C	Baud is twice the symbol rate
D	They are the same

42. - E8D09

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

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

43. - E9A01

What is an isotropic antenna?

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

44. - E9B02

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

Select	Answer
A	18 dB
B	24 dB
C	14 dB
D	36 dB

45. - E9C11

How is the far-field elevation pattern of a vertically polarized antenna affected by being mounted over seawater versus soil?

Select	Answer
A	The low-angle radiation decreases
B	The low-angle radiation increases
C	Additional higher vertical angle lobes will appear
D	Fewer vertical angle lobes will be present

46. - E9D10

What happens to feed-point impedance at the base of a fixed length HF mobile antenna when operated below its resonant frequency?

Select	Answer
A	The radiation resistance increases and the capacitive reactance increases
B	The radiation resistance decreases and the capacitive reactance increases
C	The radiation resistance decreases and the capacitive reactance decreases
D	The radiation resistance increases and the capacitive reactance decreases

47. - E9E04

What is the purpose of the series capacitor in a gamma-type antenna matching network?

Select	Answer
A	To transform the antenna impedance to a higher value
B	To cancel the inductive reactance of the matching network
C	To provide a rejection notch that prevents the radiation of harmonics
D	To provide DC isolation between the feed line and the antenna

48. - E9F13

What impedance does a 1/4-wavelength transmission line present to a generator when the line is shorted at the far end?

Select	Answer
A	Very low impedance
B	The same as the generator output impedance
C	Very high impedance
D	The same as the characteristic impedance of the transmission line

49. - E9G08

What is the process of normalization with regard to a Smith chart?

Select	Answer
A	Reassigning resistance values with regard to the reactance axis
B	Reassigning reactance values with regard to the resistance axis
C	Reassigning prime center with regard to the reactance axis
D	Reassigning impedance values with regard to the prime center

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 small, vertically oriented receiving antenna consisting of a triangular loop terminated in approximately 900 ohms
C	A stealth antenna built to look like a flagpole
D	A four-element, high-gain vertical array invented by George Pennant

Figure E7-1

Figure E7-2

Figure E7-3

Figure E9-1