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

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1. - E0A08

What does SAR measure?

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

2. - E1A04

With your transceiver displaying the carrier frequency of phone signals, you hear a DX station calling CQ on 3.601 MHz LSB. Is it legal to return the call using lower sideband on the same frequency?

Select	Answer
A	Yes, because the DX station initiated the contact
B	Yes, because the displayed frequency is within the 75 meter phone band segment
C	No, U.S. stations are not permitted to use phone emissions below 3.610 MHz
D	No, the sideband will extend beyond the edge of the phone band segment

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	A proposal must be submitted to the National Park Service
D	An Environmental Assessment must be submitted to the FCC

4. - E1C09

What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?

Select	Answer
A	2.0
B	1.0
C	3.0
D	0.5

5. - E1D12

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

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

6. - E1E07

What should a VE do if a candidate fails to comply with the examiner's instructions during an amateur operator license examination?

Select	Answer
A	Allow the candidate to complete the examination, but invalidate the results
B	Immediately terminate the candidate's examination
C	Immediately terminate everyone's examination and close the session
D	Warn the candidate that continued failure to comply will result in termination of the examination

7. - E1F09

Which of the following conditions apply when transmitting spread spectrum emissions?

Select	Answer
A	The transmission must not be used to obscure the meaning of any communication
B	All these choices are correct
C	The transmitting station must be in an area regulated by the FCC or in a country that permits SS emissions
D	A station transmitting SS emission must not cause harmful interference to other stations employing other authorized emissions

8. - E2A02

Which of the following occurs when a satellite is using an inverting linear transponder?

Select	Answer
A	Signal position in the band is reversed
B	Doppler shift is reduced because the uplink and downlink shifts are in opposite directions
C	All these choices are correct
D	Upper sideband on the uplink becomes lower sideband on the downlink, and vice versa

9. - E2B09

What hardware, other than a receiver with SSB capability and a suitable computer, is needed to decode SSTV using Digital Radio Mondiale (DRM)?

Select	Answer
A	A special IF converter
B	A special front end limiter
C	A special notch filter to remove synchronization pulses
D	No other hardware is needed

10. - E2C09

What type of equipment is commonly used to implement an amateur radio mesh network?

Select	Answer
A	A 2 meter VHF transceiver with a 1200 baud modem
B	A wireless router running custom firmware
C	A 440 MHz transceiver with a 9600 baud modem
D	An optical cable connection between the USB ports of 2 separate computers

11. - E2D05

What is one advantage of the JT65 mode?

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

12. - E2E13

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

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

13. - E3A12

What is the cause of auroral activity?

Select	Answer
A	An extreme low-pressure area in the polar regions
B	The interaction in the F2 layer between the solar wind and the Van Allen belt
C	Meteor showers concentrated in the extreme northern and southern latitudes
D	The interaction in the E layer of charged particles from the Sun with the Earth's magnetic field

14. - E3B03

What is the best time of day for transequatorial propagation?

Select	Answer
A	Afternoon or early evening
B	Morning
C	Noon
D	Late at night

15. - E3C02

What is indicated by a rising A or K index?

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

16. - E4A05

What is the purpose of the prescaler function on a frequency counter?

Select	Answer
A	It amplifies low-level signals for more accurate counting
B	It multiplies a higher frequency signal so a low-frequency counter can display the operating frequency
C	It divides a higher frequency signal so a low-frequency counter can display the input frequency
D	It prevents oscillation in a low-frequency counter circuit

17. - E4B01

Which of the following factors most affects the accuracy of a frequency counter?

Select	Answer
A	Decade divider accuracy
B	Input attenuator accuracy
C	Time base accuracy
D	Temperature coefficient of the logic

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. - E4D01

What is meant by the blocking dynamic range of a receiver?

Select	Answer
A	The difference in dB between the noise floor and the third-order intercept point
B	The minimum difference in dB between the levels of two FM signals that will cause one signal to block the other
C	The minimum difference in dB between two signals which produce third-order intermodulation products greater than the noise floor
D	The difference in dB between the noise floor and the level of an incoming signal that will cause 1 dB of gain compression

20. - E4E09

What undesirable effect can occur when using an IF noise blanker?

Select	Answer
A	FM signals can no longer be demodulated
B	The audio frequency bandwidth of the received signal might be compressed
C	Nearby signals may appear to be excessively wide even if they meet emission standards
D	Received audio in the speech range might have an echo effect

21. - E5A06

What is the magnitude of the circulating current within the components of a parallel LC circuit at resonance?

Select	Answer
A	It is at a minimum
B	It equals 1 divided by the quantity 2 times pi, multiplied by the square root of inductance L multiplied by capacitance C
C	It equals 2 multiplied by pi, multiplied by frequency, multiplied by inductance
D	It is at a maximum

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	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. - 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	Maidenhead grid
B	Faraday grid
C	Elliptical coordinates
D	Polar coordinates

24. - E5D14

What is reactive power?

Select	Answer
A	Power consumed in circuit Q
B	Power consumed in wire resistance in an inductor
C	Wattless, nonproductive power
D	Power lost because of capacitor leakage

25. - E6A11

In Figure E6-1, what is the schematic symbol for a P-channel junction FET?

Select	Answer
A	1
B	3
C	6
D	2

26. - E6B04

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

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

27. - E6C08

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

Select	Answer
A	1
B	2
C	4
D	3

28. - E6D05

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

Select	Answer
A	Ferrite toroids generally require fewer turns to produce a given inductance value
B	Ferrite toroids are easier to use with surface mount technology
C	Ferrite toroids generally have lower initial permeability
D	Ferrite toroids generally have better temperature stability

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

30. - E6F01

What absorbs the energy from light falling on a photovoltaic cell?

Select	Answer
A	Holes
B	Photons
C	Electrons
D	Protons

31. - E7A07

What logical operation does a NAND gate perform?

Select	Answer
A	It produces logic 1 at its output only when all inputs are logic 1
B	It produces logic 0 at its output only when all inputs are logic 0
C	It produces logic 0 at its output only when all inputs are logic 1
D	It produces logic 0 at its output if some but not all inputs are logic 1

32. - E7B12

What type of amplifier circuit is shown in Figure E7-1?

Select	Answer
A	Common emitter
B	Common base
C	Emitter follower
D	Common collector

33. - E7C05

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

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

34. - E7D14

What is the purpose of connecting equal-value resistors across power supply filter capacitors connected in series?

Select	Answer
A	Provide a minimum load on the supply
B	Equalize the voltage across each capacitor
C	All these choices are correct
D	Discharge the capacitors when voltage is removed

35. - E7E01

Which of the following can be used to generate FM phone emissions?

Select	Answer
A	A reactance modulator on the oscillator
B	A balanced modulator on the oscillator
C	A balanced modulator on the audio amplifier
D	A reactance modulator on the final amplifier

36. - E7F13

What is the function of taps in a digital signal processing filter?

Select	Answer
A	Provide incremental signal delays for filter algorithms
B	Provide access for debugging software
C	To reduce excess signal pressure levels
D	Select the point at which baseband signals are generated

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	0.21
B	94
C	47
D	24

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	Frequency synthesis, FM demodulation
C	Wide-band AF and RF power amplification
D	Photovoltaic conversion, optical coupling

39. - E8A06

What is the approximate ratio of PEP-to-average power in a typical single-sideband phone signal?

Select	Answer
A	25 to 1
B	100 to 1
C	1 to 1
D	2.5 to 1

40. - E8B02

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

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

41. - E8C04

What technique minimizes the bandwidth of a PSK31 signal?

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

42. - E8D05

What is the most common method of reducing key clicks?

Select	Answer
A	Reduce keying waveform rise and fall times
B	Increase keying waveform rise and fall times
C	Low-pass filters at the transmitter output
D	High-pass filters at the transmitter output

43. - E9A02

What is the effective radiated power relative to a dipole of a repeater station with 150 watts transmitter power output, 2 dB feed line loss, 2.2 dB duplexer loss, and 7 dBd antenna gain?

Select	Answer
A	1977 watts
B	286 watts
C	78.7 watts
D	420 watts

44. - E9B02

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

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

45. - E9C03

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed in phase?

Select	Answer
A	A Figure-8 end-fire along the axis of the array
B	A Figure-8 broadside to the axis of the array
C	Cardioid
D	Omni-directional

46. - E9D02

How can linearly polarized Yagi antennas be used to produce circular polarization?

Select	Answer
A	Stack two Yagis fed 90 degrees out of phase to form an array with the respective elements in parallel planes
B	Arrange two Yagis collinear to each other with the driven elements fed 180 degrees out of phase
C	Stack two Yagis fed in phase to form an array with the respective elements in parallel planes
D	Arrange two Yagis perpendicular to each other with the driven elements at the same point on the boom fed 90 degrees out of phase

47. - E9E07

What parameter describes the interactions at the load end of a mismatched transmission line?

Select	Answer
A	Characteristic impedance
B	Reflection coefficient
C	Velocity factor
D	Dielectric constant

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

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 prime center with regard to the reactance axis
C	Reassigning reactance values with regard to the resistance axis
D	Reassigning impedance values with regard to the prime center

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 stealth antenna built to look like a flagpole
D	A form of rhombic antenna terminated in a variable capacitor to provide frequency diversity

Figure E6-1

Figure E6-3

Figure E7-1

Figure E9-1