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

2. - E1A05

What is the maximum power output permitted on the 60 meter band?

Select	Answer
A	50 watts PEP effective radiated power relative to an isotropic radiator
B	100 watts PEP effective radiated power relative to an isotropic radiator
C	100 watts PEP effective radiated power relative to the gain of a half-wave dipole
D	50 watts PEP effective radiated power relative to a dipole

3. - E1B01

Which of the following constitutes a spurious emission?

Select	Answer
A	An emission outside the signal's necessary bandwidth that can be reduced or eliminated without affecting the information transmitted
B	A signal transmitted to prevent its detection by any station other than the intended recipient
C	An amateur station transmission made without the proper call sign identification
D	Any transmitted signal that unintentionally interferes with another licensed radio station

4. - E1C10

What is the permitted mean power of any spurious emission relative to the mean power of the fundamental emission from a station transmitter or external RF amplifier installed after January 1, 2003 and transmitting on a frequency below 30 MHz?

Select	Answer
A	At least 63 dB below
B	At least 43 dB below
C	At least 73 dB below
D	At least 53 dB below

5. - E1D08

Which VHF amateur bands have frequencies authorized for space stations?

Select	Answer
A	6 meters and 2 meters
B	2 meters and 1.25 meters
C	6 meters, 2 meters, and 1.25 meters
D	2 meters

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

7. - E1F01

On what frequencies are spread spectrum transmissions permitted?

Select	Answer
A	Only on amateur frequencies above 222 MHz
B	Only on amateur frequencies above 50 MHz
C	Only on amateur frequencies above 144 MHz
D	Only on amateur frequencies above 420 MHz

8. - E2A07

Which of the following types of signals can be relayed through a linear transponder?

Select	Answer
A	PSK and packet
B	SSB and SSTV
C	FM and CW
D	All these choices are correct

9. - E2B05

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

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

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 the call sign of the DX station three times, the words this is,then your call sign three times
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 your full call sign and grid square

11. - E2D01

Which of the following digital modes is designed for meteor scatter communications?

Select	Answer
A	Hellschreiber
B	WSPR
C	MSK144
D	APRS

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. - E3A13

Which of these emission modes is best for auroral propagation?

Select	Answer
A	FM
B	SSB
C	RTTY
D	CW

14. - E3B12

What is the primary characteristic of chordal hop propagation?

Select	Answer
A	Successive ionospheric refractions without an intermediate reflection from the ground
B	Propagation across the geomagnetic equator
C	Propagation away from the great circle bearing between stations
D	Signals reflected back toward the transmitting station

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	NVIS
B	Transequatorial
C	Polar
D	Sporadic E

16. - E4A09

Which of the following is good practice when using an oscilloscope probe?

Select	Answer
A	Never use a DC-coupled probe to measure an AC circuit
B	Keep the signal ground connection of the probe as short as possible
C	Never use a high-impedance probe to measure a low-impedance circuit
D	All these choices are correct

17. - E4B02

What is the significance of voltmeter sensitivity expressed in ohms per volt?

Select	Answer
A	When used as an ohmmeter, the reading in ohms divided by the ohms per volt rating will determine the voltage applied to the circuit
B	The full scale reading of the voltmeter multiplied by its ohms per volt rating will indicate the input impedance of the voltmeter
C	When used as a galvanometer, the reading in volts multiplied by the ohms per volt rating will determine the power drawn by the device under test
D	When used as an ammeter, the full scale reading in amps divided by ohms per volt rating will determine the size of shunt needed

18. - E4C04

What is the noise figure of a receiver?

Select	Answer
A	The ratio of thermal noise to atmospheric noise
B	The ratio of the noise bandwidth in hertz to the theoretical bandwidth of a resistive network
C	The ratio of atmospheric noise to phase noise
D	The ratio in dB of the noise generated by the receiver to the theoretical minimum noise

19. - E4D05

What transmitter frequencies would cause an intermodulation-product signal in a receiver tuned to 146.70 MHz when a nearby station transmits on 146.52 MHz?

Select	Answer
A	173.35 MHz and 139.40 MHz
B	146.88 MHz and 146.34 MHz
C	146.10 MHz and 147.30 MHz
D	146.34 MHz and 146.61 MHz

20. - E4E01

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

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

21. - E5A06

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

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

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

23. - E5C07

Where is the impedance of a pure resistance plotted on rectangular coordinates?

Select	Answer
A	On the vertical axis
B	On a line through the origin, slanted at 45 degrees
C	On the horizontal axis
D	On a horizontal line, offset vertically above the horizontal axis

24. - E5D01

What is the result of skin effect?

Select	Answer
A	As frequency decreases, RF current flows in a thinner layer of the conductor, closer to the surface
B	Thermal effects on the surface of the conductor decrease the impedance
C	As frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface
D	Thermal effects on the surface of the conductor increase the impedance

25. - E6A08

What term indicates the frequency at which the grounded-base current gain of a transistor has decreased to 0.7 of the gain obtainable at 1 kHz?

Select	Answer
A	Corner frequency
B	Alpha cutoff frequency
C	Alpha rejection frequency
D	Beta cutoff frequency

26. - E6B08

Which of the following is a Schottky barrier diode?

Select	Answer
A	PIN junction
B	Electrolytic rectifier
C	Metal-semiconductor junction
D	Thermionic emission diode

27. - E6C06

Why do CMOS digital integrated circuits have high immunity to noise on the input signal or power supply?

Select	Answer
A	Bandwidth is very limited
B	The input switching threshold is about one-half the power supply voltage
C	The input switching threshold is about two times the power supply voltage
D	Large bypass capacitance is inherent

28. - E6D02

What is the equivalent circuit of a quartz crystal?

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

29. - E6E06

What characteristics of the MMIC make it a popular choice for VHF through microwave circuits?

Select	Answer
A	The ability to retrieve information from a single signal even in the presence of other strong signals
B	Controlled gain, low noise figure, and constant input and output impedance over the specified frequency range
C	Nearly infinite gain, very high input impedance, and very low output impedance
D	Plate current that is controlled by a control grid

30. - E6F02

What happens to the conductivity of a photoconductive material when light shines on it?

Select	Answer
A	It becomes unstable
B	It stays the same
C	It increases
D	It decreases

31. - E7A08

What logical operation does an OR gate perform?

Select	Answer
A	It produces logic 1 at its output if any or all inputs are logic 1
B	It produces logic 1 at its output if all inputs are logic 0
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. - E7B16

What is the effect of intermodulation products in a linear power amplifier?

Select	Answer
A	Transmission of spurious signals
B	Low efficiency
C	All these choices are correct
D	Creation of parasitic oscillations

33. - E7C04

How does an impedance-matching circuit transform a complex impedance to a resistive impedance?

Select	Answer
A	It introduces transconductance to cancel the reactive part of impedance
B	It introduces negative resistance to cancel the resistive part of impedance
C	Reactive currents are dissipated in matched resistances
D	It cancels the reactive part of the impedance and changes the resistive part to a desired value

34. - E7D11

What is the function of the pass transistor in a linear voltage regulator circuit?

Select	Answer
A	Provides a stable input impedance over a wide range of source voltage
B	Permits a wide range of output voltage settings
C	Maintains nearly constant output voltage over a wide range of load current
D	Maintains nearly constant output impedance over a wide range of load current

35. - E7E10

How does a diode envelope detector function?

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

36. - E7F11

What sets the minimum detectable signal level for a direct-sampling SDR receiver in the absence of atmospheric or thermal noise?

Select	Answer
A	Reference voltage level and sample width in bits
B	Missing codes and jitter
C	Data storage transfer rate
D	Sample clock phase noise

37. - E7G10

What absolute voltage gain can be expected from the circuit in Figure E7-3 when R1 is 1800 ohms and RF is 68 kilohms?

Select	Answer
A	76
B	38
C	0.03
D	1

38. - E7H15

Which of these functions can be performed by a phase-locked loop?

Select	Answer
A	Frequency synthesis, FM demodulation
B	Photovoltaic conversion, optical coupling
C	Comparison of two digital input signals, digital pulse counter
D	Wide-band AF and RF power amplification

39. - E8A07

What determines the PEP-to-average power ratio of a single-sideband phone signal?

Select	Answer
A	Amplifier gain
B	The degree of carrier suppression
C	The frequency of the modulating signal
D	Speech characteristics

40. - E8B09

What is deviation ratio?

Select	Answer
A	The ratio of the carrier center frequency to the audio modulating frequency
B	The ratio of the audio modulating frequency to the center carrier frequency
C	The ratio of the highest audio modulating frequency to the average audio modulating frequency
D	The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency

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 improve carrier suppression
D	To simplify modulation

42. - E8D08

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

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

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	420 watts
B	78.7 watts
C	1977 watts
D	286 watts

44. - E9B11

What is a disadvantage of decreasing the number of wire segments in an antenna model below 10 segments per half-wavelength?

Select	Answer
A	The computed feed point impedance may be incorrect
B	The resulting design will favor radiation of harmonic energy
C	Ground conductivity will not be accurately modeled
D	The antenna will become mechanically unstable

45. - E9C04

What happens to the radiation pattern of an unterminated long wire antenna as the wire length is increased?

Select	Answer
A	The front-to-back ratio decreases
B	The vertical angle increases
C	The lobes align more in the direction of the wire
D	The lobes become more perpendicular to the wire

46. - E9D02

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

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

47. - E9E09

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

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

48. - E9F07

How does ladder line compare to small-diameter coaxial cable such as RG-58 at 50 MHz?

Select	Answer
A	Lower loss
B	Higher SWR
C	Lower velocity factor
D	Smaller reflection coefficient

49. - E9G06

On the Smith chart shown in Figure E9-3, what is the name for the large outer circle on which the reactance arcs terminate?

Select	Answer
A	Prime axis
B	Impedance axis
C	Reactance axis
D	Polar axis

50. - E9H05

What is the main drawback of a small wire-loop antenna for direction finding?

Select	Answer
A	All these choices are correct
B	It has no clearly defined null
C	It is practical for use only on VHF and higher bands
D	It has a bidirectional pattern

Figure E7-3

Figure E9-3