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

2. - E1A10

If an amateur station is installed aboard a ship or aircraft, what condition must be met before the station is operated?

Select	Answer
A	The amateur station must have a power supply that is completely independent of the main ship or aircraft power supply
B	Its operation must be approved by the master of the ship or the pilot in command of the aircraft
C	The amateur station operator must agree not to transmit when the main radio of the ship or aircraft is in use
D	The amateur operator must have an FCC Marine or Aircraft endorsement on his or her amateur license

3. - E1B12

What must the control operator of a repeater operating in the 70 cm band do if a radiolocation system experiences interference from that repeater?

Select	Answer
A	File an FAA NOTAM (Notice to Airmen) with the repeater system's ERP, call sign, and six-character grid locator
B	All these choices are correct
C	Reduce the repeater antenna HAAT (Height Above Average Terrain)
D	Cease operation or make changes to the repeater to mitigate the interference

4. - E1C14

How long must an operator wait after filing a notification with the Utilities Technology Council (UTC) before operating on the 2200 meter or 630 meter band?

Select	Answer
A	Operations may commence immediately, and may continue unless interference is reported by the UTC
B	Operators may operate after 30 days, providing they have not been told that their station is within 1 km of PLC systems using those frequencies
C	Operators may not operate until a test signal has been transmitted in coordination with the local power company
D	Operators must not operate until approval is received

5. - E1D04

Which of the following is required in the identification transmissions from a balloon-borne telemetry station?

Select	Answer
A	All these choices are correct
B	The output power of the balloon transmitter
C	The station's six-character Maidenhead grid locator
D	Call sign

6. - E1E09

What may be the penalty for a VE who fraudulently administers or certifies an examination?

Select	Answer
A	Revocation of the VE's amateur station license grant and the suspension of the VE's amateur operator license grant
B	All these choices are correct
C	A fine of up to $1000 per occurrence
D	A sentence of up to one year in prison

7. - E1F02

What privileges are authorized in the U.S. to persons holding an amateur service license granted by the government of Canada?

Select	Answer
A	None, they must obtain a U.S. license
B	Full privileges, up to and including those of the Amateur Extra Class license, on the 80, 40, 20, 15, and 10 meter bands
C	All privileges of the Amateur Extra Class license
D	The operating terms and conditions of the Canadian amateur service license, not to exceed U.S. Amateur Extra Class license privileges

8. - E2A09

What do the terms L band and S band specify regarding satellite communications?

Select	Answer
A	Which sideband to use
B	The 2 meter and 70 centimeter bands
C	FM and Digital Store-and-Forward systems
D	The 23 centimeter and 13 centimeter bands

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. - E2C10

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

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

11. - E2D10

How can an APRS station be used to help support a public service communications activity?

Select	Answer
A	An APRS station with a Global Positioning System unit can automatically transmit information to show a mobile station's position during the event
B	All these choices are correct
C	APRS stations with General Personnel Scanners can automatically relay the participant numbers and time as they pass the check points
D	An APRS station with an emergency medical technician can automatically transmit medical data to the nearest hospital

12. - E2E09

Which of the following HF digital modes uses variable-length coding for bandwidth efficiency?

Select	Answer
A	PSK31
B	RTTY
C	MT63
D	PACTOR

13. - E3A10

Which type of atmospheric structure can create a path for microwave propagation?

Select	Answer
A	The jet stream
B	Wind shear
C	Temperature inversion
D	Dust devil

14. - E3B11

At what time of day can sporadic E propagation occur?

Select	Answer
A	Only around sunset and sunrise
B	Only in hours of darkness
C	Only around sunset
D	Any time

15. - E3C14

Why does the radio-path horizon distance exceed the geometric horizon?

Select	Answer
A	E-region skip
B	D-region skip
C	Due to the Doppler effect
D	Downward bending due to density variations in the atmosphere

16. - E4A10

Which of the following displays multiple digital signal states simultaneously?

Select	Answer
A	Logic analyzer
B	Modulation monitor
C	Bit error rate tester
D	Network analyzer

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	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
C	The full scale reading of the voltmeter multiplied by its ohms per volt rating will indicate the input impedance of the voltmeter
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 in dB of the noise generated by the receiver to the theoretical minimum noise
C	The ratio of the noise bandwidth in hertz to the theoretical bandwidth of a resistive network
D	The ratio of atmospheric noise to phase noise

19. - E4D12

What is the term for the reduction in receiver sensitivity caused by a strong signal near the received frequency?

Select	Answer
A	Desensitization
B	Quieting
C	Squelch gain rollback
D	Cross-modulation interference

20. - E4E08

What current flows equally on all conductors of an unshielded multi-conductor cable?

Select	Answer
A	Reactive current only
B	Common-mode current
C	Differential-mode current
D	Return current

21. - E5A05

What is the result of increasing the Q of an impedance-matching circuit?

Select	Answer
A	Matching range is increased
B	It has no effect on impedance matching
C	Matching bandwidth is decreased
D	Matching bandwidth is increased

22. - E5B07

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 500 ohms, R is 1 kilohm, and XL is 250 ohms?

Select	Answer
A	14.0 degrees with the voltage lagging the current
B	68.2 degrees with the voltage lagging the current
C	68.2 degrees with the voltage leading the current
D	14.0 degrees with the voltage leading the current

23. - E5C05

What is the name of the diagram used to show the phase relationship between impedances at a given frequency?

Select	Answer
A	Near field diagram
B	Venn diagram
C	Phasor diagram
D	Far field diagram

24. - E5D03

What is microstrip?

Select	Answer
A	Lightweight transmission line made of common zip cord
B	Miniature coax used for low power applications
C	Precision printed circuit conductors above a ground plane that provide constant impedance interconnects at microwave frequencies
D	Short lengths of coax mounted on printed circuit boards to minimize time delay between microwave circuits

25. - E6A11

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

Select	Answer
A	3
B	6
C	1
D	2

26. - E6B02

What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

Select	Answer
A	More constant reverse avalanche voltage
B	Much higher reverse voltage breakdown
C	Less forward voltage drop
D	Longer carrier retention time

27. - E6C03

What is tri-state logic?

Select	Answer
A	Low-power logic devices designed to operate at 3 volts
B	Proprietary logic devices manufactured by Tri-State Devices
C	Logic devices with 0, 1, and high-impedance output states
D	Logic devices that utilize ternary math

28. - E6D12

What is inductor saturation?

Select	Answer
A	The ability of the inductor's core to store magnetic energy has been exceeded
B	The inductor's voltage rating is exceeded causing a flashover
C	Adjacent inductors become over-coupled
D	The inductor windings are over-coupled

29. - E6E03

Which of the following materials is likely to provide the highest frequency of operation when used in MMICs?

Select	Answer
A	Silicon
B	Silicon nitride
C	Gallium nitride
D	Silicon dioxide

30. - E6F10

What is the most common type of photovoltaic cell used for electrical power generation?

Select	Answer
A	Silicon
B	Cadmium Sulfide
C	Selenium
D	Copper oxide

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 1
C	It produces logic 0 at its output only when all inputs are logic 0
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 collector
C	Emitter follower
D	Common base

33. - E7C01

How are the capacitors and inductors of a low-pass filter Pi-network arranged between the network's input and output?

Select	Answer
A	A capacitor is connected between the input and ground, another capacitor is connected between the output and ground, and an inductor is connected between input and output
B	Two inductors are in series between the input and output, and a capacitor is connected between the two inductors and ground
C	Two capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground
D	An inductor is connected between the input and ground, another inductor is connected between the output and ground, and a capacitor is connected between the input and output

34. - E7D08

What type of circuit is shown in Figure E7-2?

Select	Answer
A	Linear voltage regulator
B	Monostable multivibrator
C	Grounded emitter amplifier
D	Switching voltage regulator

35. - E7E09

What occurs when an excessive amount of signal energy reaches a mixer circuit?

Select	Answer
A	Mixer blanking occurs
B	Spurious mixer products are generated
C	Automatic limiting occurs
D	A beat frequency is generated

36. - E7F07

What function is performed by a Fast Fourier Transform?

Select	Answer
A	Converting analog signals to digital form
B	Converting 8-bit data to 16-bit data
C	Converting digital signals to analog form
D	Converting digital signals from the time domain to the frequency domain

37. - E7G05

How can unwanted ringing and audio instability be prevented in an op-amp RC audio filter circuit?

Select	Answer
A	Increase both gain and Q
B	Restrict both gain and Q
C	Restrict Q but increase gain
D	Restrict gain but increase Q

38. - E7H13

Which of the following is a technique for providing highly accurate and stable oscillators needed for microwave transmission and reception?

Select	Answer
A	Use a rubidium stabilized reference oscillator
B	Use a GPS signal reference
C	All these choices are correct
D	Use a temperature-controlled high Q dielectric resonator

39. - E8A06

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

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

40. - E8B05

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus-or-minus 5 kHz when the maximum modulation frequency is 3 kHz?

Select	Answer
A	0.167
B	1.67
C	0.6
D	60

41. - E8C10

How may data rate be increased without increasing bandwidth?

Select	Answer
A	It is impossible
B	Using forward error correction
C	Using a more efficient digital code
D	Increasing analog-to-digital conversion resolution

42. - E8D06

What is the advantage of including parity bits in ASCII characters?

Select	Answer
A	The signal can overpower interfering signals
B	Foreign language characters can be sent
C	Some types of errors can be detected
D	Faster transmission rate

43. - E9A03

What is the radiation resistance of an antenna?

Select	Answer
A	The combined losses of the antenna elements and feed line
B	The value of a resistance that would dissipate the same amount of power as that radiated from an antenna
C	The resistance in the atmosphere that an antenna must overcome to be able to radiate a signal
D	The specific impedance of the antenna

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	24 dB
C	18 dB
D	14 dB

45. - E9C07

What is the approximate feed point impedance at the center of a two-wire folded dipole antenna?

Select	Answer
A	450 ohms
B	300 ohms
C	72 ohms
D	50 ohms

46. - E9D03

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

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

48. - E9F08

Which of the following is a significant difference between foam dielectric coaxial cable and solid dielectric cable, assuming all other parameters are the same?

Select	Answer
A	Foam dielectric has lower loss per unit of length
B	All these choices are correct
C	Foam dielectric has lower safe operating voltage limits
D	Foam dielectric has higher velocity factor

49. - E9G10

What do the arcs on a Smith chart represent?

Select	Answer
A	SWR
B	Frequency
C	Points with constant reactance
D	Points with constant resistance

50. - E9H03

What is Receiving Directivity Factor (RDF)?

Select	Answer
A	Relative directivity compared to a dipole
B	Forward gain compared to the gain in the reverse direction
C	Relative directivity compared to isotropic
D	Forward gain compared to average gain over the entire hemisphere

Figure E6-1

Figure E7-1

Figure E7-2

Figure E9-1