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

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1. - E0A06

Why are there separate electric (E) and magnetic (H) field MPE limits?

Select	Answer
A	The body reacts to electromagnetic radiation from both the E and H fields
B	Ground reflections and scattering make the field strength vary with location
C	All these choices are correct
D	E field and H field radiation intensity peaks can occur at different locations

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

3. - E1B10

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

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

4. - E1C09

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

Select	Answer
A	3.0
B	1.0
C	2.0
D	0.5

5. - E1D07

Which HF amateur bands have frequencies authorized for space stations?

Select	Answer
A	All HF bands
B	Only the 40, 20, 17, 15, 12, and 10 meter bands
C	Only the 40, 30, 20, 15, 12, and 10 meter bands
D	Only the 40, 20, 17, 15, and 10 meter bands

6. - E1E10

What must the administering VEs do after the administration of a successful examination for an amateur operator license?

Select	Answer
A	They must collect and send the documents to the FCC according to instructions
B	They must collect and send the documents to the NCVEC for grading
C	They must submit the application document to the coordinating VEC according to the coordinating VEC instructions
D	They must collect and submit the documents to the coordinating VEC for grading

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

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. - E2B06

What is vestigial sideband modulation?

Select	Answer
A	Narrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier
B	Amplitude modulation in which one complete sideband and a portion of the other are transmitted
C	A type of modulation in which one sideband is inverted
D	Spread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation

10. - E2C12

What technique do individual nodes use to form a mesh network?

Select	Answer
A	Forward error correction and Viterbi codes
B	Custom code plugs for the local trunking systems
C	Discovery and link establishment protocols
D	Acting as store-and-forward digipeaters

11. - E2D01

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

Select	Answer
A	MSK144
B	APRS
C	WSPR
D	Hellschreiber

12. - E2E02

What do the letters FEC mean as they relate to digital operation?

Select	Answer
A	Forward Error Correction
B	Final Error Correction
C	First Error Correction
D	Fatal Error Correction

13. - E3A01

What is the approximate maximum separation measured along the surface of the Earth between two stations communicating by EME?

Select	Answer
A	500 miles, if the moon is at perigee
B	5000 miles, if the moon is at perigee
C	2000 miles, if the moon is at apogee
D	12,000 miles, if the moon is visible by both stations

14. - E3B01

What is transequatorial propagation?

Select	Answer
A	Propagation between two mid-latitude points at approximately the same distance north and south of the magnetic equator
B	Propagation between a point on the equator and its antipodal point
C	Propagation between points at the same latitude
D	Propagation between points located on the magnetic equator

15. - E3C08

What does the space weather term G5 mean?

Select	Answer
A	Moderate solar wind
B	Very low solar activity
C	An extreme geomagnetic storm
D	Waning sunspot numbers

16. - E4A07

Which of the following is an advantage of using an antenna analyzer compared to an SWR bridge to measure antenna SWR?

Select	Answer
A	Antenna analyzers do not need an external RF source
B	All these choices are correct
C	Antenna analyzers automatically tune your antenna for resonance
D	Antenna analyzers display a time-varying representation of the modulation envelope

17. - E4B04

Which S parameter represents input port return loss or reflection coefficient (equivalent to VSWR)?

Select	Answer
A	S11
B	S21
C	S12
D	S22

18. - E4C12

Which of the following has the largest effect on an SDR receiver's dynamic range?

Select	Answer
A	CPU register width in bits
B	RAM speed used for data storage
C	Anti-aliasing input filter bandwidth
D	Analog-to-digital converter sample width in bits

19. - E4D01

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

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

20. - E4E09

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

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

21. - E5A11

What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150?

Select	Answer
A	315.6 Hz
B	23.67 kHz
C	157.8 Hz
D	47.3 kHz

22. - E5B10

What is the relationship between the AC current through an inductor and the voltage across an inductor?

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

23. - E5C12

Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and a 19-picofarad capacitor at 21.200 MHz?

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

24. - E5D13

How many watts are consumed in a circuit consisting of a 100-ohm resistor in series with a 100-ohm inductive reactance drawing 1 ampere?

Select	Answer
A	141.4 watts
B	200 watts
C	100 watts
D	70.7 watts

25. - E6A01

In what application is gallium arsenide used as a semiconductor material?

Select	Answer
A	In high-current rectifier circuits
B	In very low-frequency RF circuits
C	In high-power audio circuits
D	In microwave circuits

26. - E6B08

Which of the following is a Schottky barrier diode?

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

27. - E6C08

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

Select	Answer
A	1
B	4
C	2
D	3

28. - E6D08

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

Select	Answer
A	Powdered-iron cores generally have greater initial permeability
B	Powdered-iron cores generally require fewer turns to produce a given inductance
C	Powdered-iron cores use smaller diameter wire for the same inductance
D	Powdered-iron cores generally maintain their characteristics at higher currents

29. - E6E02

Which of the following device packages is a through-hole type?

Select	Answer
A	DIP
B	PLCC
C	SOT
D	Ball grid array

30. - E6F08

Why are optoisolators often used in conjunction with solid-state circuits when switching 120 VAC?

Select	Answer
A	Optoisolators provide a low impedance link between a control circuit and a power circuit
B	Optoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched
C	Optoisolators provide impedance matching between the control circuit and power circuit
D	Optoisolators eliminate the effects of reflected light in the control circuit

31. - E7A02

What is the function of a decade counter?

Select	Answer
A	It decodes a binary number for display on a seven-segment LED display
B	It produces one output pulse for every 10 input pulses
C	It produces 10 output pulses for every input pulse
D	It decodes a decimal number for display on a seven-segment LED display

32. - E7B15

What is one way to prevent thermal runaway in a bipolar transistor amplifier?

Select	Answer
A	Use a resistor in series with the emitter
B	Neutralization
C	Select transistors with high beta
D	All these choices are correct

33. - E7C02

Which of the following is a property of a T-network with series capacitors and a parallel shunt inductor?

Select	Answer
A	It is a band-pass filter
B	It is a high-pass filter
C	It is a notch filter
D	It is a low-pass filter

34. - E7D10

What is the primary reason that a high-frequency switching type high-voltage power supply can be both less expensive and lighter in weight than a conventional power supply?

Select	Answer
A	It uses a large power factor compensation capacitor to recover power from the unused portion of the AC cycle
B	It uses a diode bridge rectifier for increased output
C	The inverter design does not require any output filtering
D	The high frequency inverter design uses much smaller transformers and filter components for an equivalent power output

35. - E7E04

What is one way a single-sideband phone signal can be generated?

Select	Answer
A	By driving a product detector with a DSB signal
B	By using a reactance modulator followed by a mixer
C	By using a loop modulator followed by a mixer
D	By using a balanced modulator followed by a filter

36. - E7F01

What is meant by direct digital conversion as applied to software defined radios?

Select	Answer
A	A switching mixer is used to generate I and Q signals directly from the RF input
B	Incoming RF is converted to a control voltage for a voltage controlled oscillator
C	Software is converted from source code to object code during operation of the receiver
D	Incoming RF is digitized by an analog-to-digital converter without being mixed with a local oscillator signal

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	47
B	24
C	0.21
D	94

38. - E7H07

How can an oscillator's microphonic responses be reduced?

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

39. - E8A01

What is the name of the process that shows that a square wave is made up of a sine wave plus all its odd harmonics?

Select	Answer
A	Numerical analysis
B	Differential analysis
C	Vector analysis
D	Fourier analysis

40. - E8B04

What is the modulation index of an FM-phone signal having a maximum carrier deviation of plus or minus 6 kHz when modulated with a 2 kHz modulating frequency?

Select	Answer
A	6000
B	3
C	2000
D	1/3

41. - E8C07

What is the bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?

Select	Answer
A	9.6 kHz
B	4.8 kHz
C	15.36 kHz
D	5.76 kHz

42. - E8D07

What is a common cause of overmodulation of AFSK signals?

Select	Answer
A	Ground loops
B	Excessive transmit audio levels
C	Bit errors in the modem
D	Excessive numbers of retries

43. - E9A10

Which of the following improves the efficiency of a ground-mounted quarter-wave vertical antenna?

Select	Answer
A	All these choices are correct
B	Shortening the radiating element
C	Installing a radial system
D	Isolating the coax shield from ground

44. - E9B09

What type of computer program technique is commonly used for modeling antennas?

Select	Answer
A	Graphical analysis
B	Method of Moments
C	Calculus differentiation with respect to physical properties
D	Mutual impedance analysis

45. - E9C05

Which of the following is a type of OCFD antenna?

Select	Answer
A	A remotely tunable dipole antenna using orthogonally controlled frequency diversity
B	A dipole fed approximately 1/3 the way from one end with a 4:1 balun to provide multiband operation
C	A multiband dipole antenna using one-way circular polarization for frequency diversity
D	A folded dipole center-fed with 300-ohm transmission line

46. - E9D07

What is an advantage of using top loading in a shortened HF vertical antenna?

Select	Answer
A	Higher losses
B	Lower Q
C	Greater structural strength
D	Improved radiation efficiency

47. - E9E03

What is the name of the matching system that uses a section of transmission line connected in parallel with the feed line at or near the feed point?

Select	Answer
A	The stub match
B	The delta match
C	The gamma match
D	The omega match

48. - E9F05

What is the approximate physical length of a solid polyethylene dielectric coaxial transmission line that is electrically 1/4 wavelength long at 14.1 MHz?

Select	Answer
A	5.3 meters
B	3.5 meters
C	10.6 meters
D	4.3 meters

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	Reactance axis
B	Impedance axis
C	Polar axis
D	Prime 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 has a bidirectional pattern
D	It is practical for use only on VHF and higher bands

Figure E5-1

Figure E6-3

Figure E9-3