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	Each transmitter that produces 5 percent or more of its MPE limit in areas where the total MPE limit is exceeded.
C	Only the most powerful transmitter
D	Only commercial transmitters

2. - E1A14

Except in some parts of Alaska, what is the maximum power permitted on the 630 meter band?

Select	Answer
A	5 watts EIRP
B	50 watts PEP
C	100 watts PEP
D	1 watt EIRP

3. - E1B02

Which of the following is an acceptable bandwidth for Digital Radio Mondiale (DRM) based voice or SSTV digital transmissions made on the HF amateur bands?

Select	Answer
A	3 kHz
B	10 kHz
C	15 kHz
D	20 kHz

4. - E1C13

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

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

5. - E1D06

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

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

6. - E1E08

To which of the following examinees may a VE not administer an examination?

Select	Answer
A	All these choices are correct
B	Friends of the VE
C	Employees of the VE
D	Relatives of the VE as listed in the FCC rules

7. - E1F06

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

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

8. - E2A04

What is meant by the term mode? as applied to an amateur radio satellite?

Select	Answer
A	The satellite's uplink and downlink frequency bands
B	Whether the satellite is in a low earth or geostationary orbit
C	The satellite's orientation with respect to the Earth
D	Whether the satellite is in a polar or equatorial orbit

9. - E2B02

How many horizontal lines make up a fast-scan (NTSC) television frame?

Select	Answer
A	525
B	1080
C	30
D	60

10. - E2C10

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

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

11. - E2D05

What is one advantage of the JT65 mode?

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

12. - E2E13

Which of these digital modes has the fastest data throughput under clear communication conditions?

Select	Answer
A	PSK31
B	300 baud packet
C	AMTOR
D	170 Hz shift, 45 baud RTTY

13. - E3A09

Which of the following frequency ranges is most suited for meteor scatter communications?

Select	Answer
A	10 MHz - 14 MHz
B	28 MHz - 148 MHz
C	220 MHz - 450 MHz
D	1.8 MHz - 1.9 MHz

14. - E3B04

What is meant by the terms "extraordinary" and "ordinary" waves?

Select	Answer
A	Long-path and short-path waves
B	Independent waves created in the ionosphere that are elliptically polarized
C	Refracted rays and reflected waves
D	Extraordinary waves describe rare long-skip propagation compared to ordinary waves, which travel shorter distances

15. - E3C06

By how much does the VHF/UHF radio horizon distance exceed the geometric horizon?

Select	Answer
A	By approximately four times the distance
B	By approximately twice the distance
C	By approximately 15 percent of the distance
D	By approximately 50 percent of the distance

16. - E4A06

What is the effect of aliasing on a digital oscilloscope caused by setting the time base too slow?

Select	Answer
A	Excessive blanking occurs, which prevents display of the signal
B	A false, jittery low-frequency version of the signal is displayed
C	All signals will have a DC offset
D	Calibration of the vertical scale is no longer valid

17. - E4B05

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

Select	Answer
A	Short circuit, open circuit, and 50 ohms
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 resonant circuit

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

19. - E4D10

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

Select	Answer
A	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
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	Signals less than 40 dBm will not generate audible third-order intermodulation products

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	Broadband white noise
C	Ignition noise
D	All these choices are correct

21. - E5A08

What is the phase relationship between the current through and the voltage across a series resonant circuit at resonance?

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

22. - E5B04

What is the time constant of a circuit having two 220-microfarad capacitors and two 1-megohm resistors, all in parallel?

Select	Answer
A	220 seconds
B	440 seconds
C	110 seconds
D	55 seconds

23. - E5C11

Which point in Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and an 18-microhenry inductor at 3.505 MHz?

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

24. - E5D06

In what direction is the magnetic field oriented about a conductor in relation to the direction of electron flow?

Select	Answer
A	In a direction opposite to the current
B	In the same direction as the current
C	In a circle around the conductor
D	In all directions; omni-directional

25. - E6A02

Which of the following semiconductor materials contains excess free electrons?

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

26. - E6B05

What characteristic of a PIN diode makes it useful as an RF switch?

Select	Answer
A	Extremely high reverse breakdown voltage
B	Reverse bias controls its forward voltage drop
C	Ability to dissipate large amounts of power
D	Low junction capacitance

27. - E6C10

In Figure E6-3, what is the schematic symbol for a NOR gate?

Select	Answer
A	1
B	3
C	2
D	4

28. - E6D01

Why should core saturation of an impedance matching transformer be avoided?

Select	Answer
A	Harmonics and distortion could result
B	Magnetic flux would increase with frequency
C	Temporary changes of the core permeability could result
D	RF susceptance would increase

29. - E6E10

What advantage does surface-mount technology offer at RF compared to using through-hole components?

Select	Answer
A	Smaller circuit area
B	All these choices are correct
C	Components have less parasitic inductance and capacitance
D	Shorter circuit-board traces

30. - E6F11

What is the approximate open-circuit voltage produced by a fully illuminated silicon photovoltaic cell?

Select	Answer
A	1.5 V
B	0.5 V
C	0.1 V
D	12 V

31. - E7A10

What is a truth table?

Select	Answer
A	A list of inputs and corresponding outputs for a digital device
B	A table of logic symbols that indicate the logic states of an op-amp
C	A table of logic symbols that indicate the high logic states of an op-amp
D	A diagram showing logic states when the digital device output is true

32. - E7B11

In Figure E7-1, what is the purpose of R3?

Select	Answer
A	Self bias
B	Fixed bias
C	Emitter bypass
D	Output load resistor

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. - E7D09

What is the main reason to use a charge controller with a solar power system?

Select	Answer
A	Prevention of battery damage due to overcharge
B	Matching of day and night charge rates
C	Control of electrolyte levels during battery discharge
D	Prevention of battery undercharge

35. - E7E03

What is a frequency discriminator stage in a FM receiver?

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

36. - E7F08

What is the function of decimation?

Select	Answer
A	Removing unnecessary significant digits
B	Reducing the effective sample rate by removing samples
C	Attenuating the signal
D	Converting data to binary code decimal form

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	24
B	94
C	47
D	0.21

38. - E7H07

How can an oscillator's microphonic responses be reduced?

Select	Answer
A	Increase the bias voltage
B	Mechanically isolate the oscillator circuitry from its enclosure
C	Use NP0 capacitors
D	Reduce noise on the oscillator's power supply

39. - E8A08

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

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

40. - E8B06

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz when the maximum modulation frequency is 3.5 kHz?

Select	Answer
A	0.47
B	47
C	2.14
D	0.214

41. - E8C03

Why should phase-shifting of a PSK signal be done at the zero crossing of the RF signal?

Select	Answer
A	To minimize bandwidth
B	All these choices are correct
C	To simplify modulation
D	To improve carrier suppression

42. - E8D04

What is the primary effect of extremely short rise or fall time on a CW signal?

Select	Answer
A	The generation of RF harmonics
B	More difficult to copy
C	Limits data speed
D	The generation of key clicks

43. - E9A04

Which of the following factors affect the feed point impedance of an antenna?

Select	Answer
A	The input power level
B	Antenna height
C	Transmission line length
D	The settings of an antenna tuner at the transmitter

44. - E9B02

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

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

45. - E9C12

Which of the following describes an Extended Double Zepp antenna?

Select	Answer
A	A wideband vertical antenna constructed from precisely tapered aluminum tubing
B	An end-fed folded dipole antenna
C	A center-fed 1.25-wavelength antenna (two 5/8-wave elements in phase)
D	A portable antenna erected using two push support poles

46. - E9D03

Where should a high Q loading coil be placed to minimize losses in a shortened vertical antenna?

Select	Answer
A	As close to the transmitter as possible
B	At a voltage node
C	Near the center of the vertical radiator
D	As low as possible on the vertical radiator

47. - E9E08

What is a use for a Wilkinson divider?

Select	Answer
A	It is used to divide power equally between two 50-ohm loads while maintaining 50-ohm input impedance
B	It is used to feed high-impedance antennas from a low-impedance source
C	It divides the operating frequency of a transmitter signal so it can be used on a lower frequency band
D	It is used to feed low-impedance loads from a high-impedance source

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

49. - E9G09

What third family of circles is often added to a Smith chart during the process of solving problems?

Select	Answer
A	Standing wave ratio circles
B	Radiation-pattern circles
C	Coaxial-length circles
D	Antenna-length circles

50. - E9H01

When constructing a Beverage antenna, which of the following factors should be included in the design to achieve good performance at the desired frequency?

Select	Answer
A	Its overall length must not exceed 1/4 wavelength
B	It should be one or more wavelengths long
C	It should be configured as a four-sided loop
D	It must be mounted more than 1 wavelength above ground

Figure E5-1

Figure E6-3

Figure E7-1

Figure E9-1