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

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1. - E0A09

Which insulating material commonly used as a thermal conductor for some types of electronic devices is extremely toxic if broken or crushed and the particles are accidentally inhaled?

Select	Answer
A	Zinc oxide
B	Beryllium Oxide
C	Mica
D	Uranium Hexafluoride

2. - E1A09

What action or actions should you take if your digital message forwarding station inadvertently forwards a communication that violates FCC rules?

Select	Answer
A	All these choices are correct
B	Discontinue forwarding the communication as soon as you become aware of it
C	Notify the nearest FCC Field Engineers office
D	Notify the originating station that the communication does not comply with FCC rules

3. - E1B09

Which amateur stations may be operated under RACES rules?

Select	Answer
A	Any FCC-licensed amateur station except a Technician Class
B	Any FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)
C	Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served
D	Only those club stations licensed to Amateur Extra Class operators

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. - E1D01

What is the definition of telemetry?

Select	Answer
A	Two-way transmissions of data
B	One-way transmission of measurements at a distance from the measuring instrument
C	Two-way transmissions in excess of 1000 feet
D	One-way transmission that initiates, modifies, or terminates the functions of a device at a distance

6. - E1E09

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

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

7. - E1F06

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

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

8. - E2A04

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

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

9. - E2B01

How many times per second is a new frame transmitted in a fast-scan (NTSC) television system?

Select	Answer
A	120
B	60
C	90
D	30

10. - E2C01

What indicator is required to be used by U.S.-licensed operators when operating a station via remote control and the remote transmitter is located in the U.S.?

Select	Answer
A	No additional indicator is required
B	/ followed by the USPS two-letter abbreviation for the state in which the remote station is located
C	/ followed by the ARRL Section of the remote station
D	/R# where # is the district of the remote station

11. - E2D05

What is one advantage of the JT65 mode?

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

12. - E2E09

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

Select	Answer
A	PACTOR
B	RTTY
C	PSK31
D	MT63

13. - E3A06

What might help to restore contact when DX signals become too weak to copy across an entire HF band a few hours after sunset?

Select	Answer
A	Wait 24 hours before attempting another communication on the band
B	Switch to a higher frequency HF band
C	Switch to a lower frequency HF band
D	Wait 90 minutes or so for the signal degradation to pass

14. - E3B11

At what time of day can sporadic E propagation occur?

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

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	Polar
C	Transequatorial
D	Sporadic E

16. - E4A03

Which of the following test instruments is used to display spurious signals and/or intermodulation distortion products generated by an SSB transmitter?

Select	Answer
A	A logic analyzer
B	A wattmeter
C	A time-domain reflectometer
D	A spectrum analyzer

17. - E4B07

What do the subscripts of S parameters represent?

Select	Answer
A	The relative time between measurements
B	Relative quality of the data
C	Frequency order of the measurements
D	The port or ports at which measurements are made

18. - E4C03

What is the term for the suppression in an FM receiver of one signal by another stronger signal on the same frequency?

Select	Answer
A	Desensitization
B	Frequency discrimination
C	Cross-modulation interference
D	Capture effect

19. - E4D12

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

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

20. - E4E11

What could cause local AM broadcast band signals to combine to generate spurious signals in the MF or HF bands?

Select	Answer
A	One or more of the broadcast stations is transmitting an over-modulated signal
B	You are receiving skywave signals from a distant station
C	Your station receiver IF amplifier stage is defective
D	Nearby corroded metal joints are mixing and re-radiating the broadcast signals

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	47.3 kHz
C	157.8 Hz
D	23.67 kHz

22. - E5B06

What is susceptance?

Select	Answer
A	The ratio of magnetic field to electric field
B	A measure of the efficiency of a transformer
C	The imaginary part of admittance
D	The magnetic impedance of a circuit

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	Polar coordinates
B	Maidenhead grid
C	Faraday grid
D	Elliptical coordinates

24. - E5D07

How many watts are consumed in a circuit having a power factor of 0.71 if the apparent power is 500VA?

Select	Answer
A	252 W
B	704 W
C	1.42 mW
D	355 W

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	Alpha cutoff frequency
B	Alpha rejection frequency
C	Corner frequency
D	Beta cutoff frequency

26. - E6B03

What type of bias is required for an LED to emit light?

Select	Answer
A	Forward bias
B	Reverse bias
C	Inductive bias
D	Zero bias

27. - E6C01

What is the function of hysteresis in a comparator?

Select	Answer
A	To allow the comparator to be used with AC input signals
B	To increase the sensitivity
C	To prevent input noise from causing unstable output signals
D	To cause the output to change states continually

28. - E6D03

Which of the following is an aspect of the piezoelectric effect?

Select	Answer
A	Mechanical deformation of material by the application of a magnetic field
B	Increased conductivity in the presence of light
C	Mechanical deformation of material by the application of a voltage
D	Generation of electrical energy in the presence of light

29. - E6E04

Which is the most common input and output impedance of circuits that use MMICs?

Select	Answer
A	300 ohms
B	50 ohms
C	10 ohms
D	450 ohms

30. - E6F07

What is a solid-state relay?

Select	Answer
A	A semiconductor passive delay line
B	A mechanical relay that latches in the on or off state each time it is pulsed
C	A relay using transistors to drive the relay coil
D	A device that uses semiconductors to implement the functions of an electromechanical relay

31. - E7A03

Which of the following can divide the frequency of a pulse train by 2?

Select	Answer
A	An OR gate
B	A multiplexer
C	An XOR gate
D	A flip-flop

32. - E7B03

Which of the following components form the output of a class D amplifier circuit?

Select	Answer
A	A high-pass filter to compensate for low gain at low frequencies
B	A temperature compensating load resistor to improve linearity
C	A matched load resistor to prevent damage by switching transients
D	A low-pass filter to remove switching signal components

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 notch filter
B	It is a band-pass filter
C	It is a high-pass filter
D	It is a low-pass 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	Discharge the capacitors when voltage is removed
D	All these choices are correct

35. - E7E06

Why is de-emphasis commonly used in FM communications receivers?

Select	Answer
A	For compatibility with transmitters using phase modulation
B	For higher efficiency
C	To reduce impulse noise reception
D	To remove third-order distortion products

36. - E7F07

What function is performed by a Fast Fourier Transform?

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

37. - E7G06

What is the gain-bandwidth of an operational amplifier?

Select	Answer
A	The gain of the amplifier at a filter's cutoff frequency
B	The frequency at which the amplifier's offset voltage is zero
C	The frequency at which the open-loop gain of the amplifier equals one
D	The maximum frequency for a filter circuit using that type of amplifier

38. - E7H09

What type of frequency synthesizer circuit uses a phase accumulator, lookup table, digital to analog converter, and a low-pass anti-alias filter?

Select	Answer
A	A phase-locked loop synthesizer
B	A direct digital synthesizer
C	A hybrid synthesizer
D	A diode-switching matrix synthesizer

39. - E8A09

How many different input levels can be encoded by an analog-to-digital converter with 8-bit resolution?

Select	Answer
A	8
B	256 divided by the gain of the input amplifier
C	8 multiplied by the gain of the input amplifier
D	256

40. - E8B11

What is digital time division multiplexing?

Select	Answer
A	Two or more signals are arranged to share discrete time slots of a data transmission
B	Two or more data streams are assigned to discrete sub-carriers on an FM transmitter
C	Two or more data streams share the same channel by transmitting time of transmission as the sub-carrier
D	Two or more signals are quadrature modulated to increase bandwidth efficiency

41. - E8C01

How is Forward Error Correction implemented?

Select	Answer
A	By transmitting extra data that may be used to detect and correct transmission errors
B	By the receiving station repeating each block of three data characters
C	By transmitting a special algorithm to the receiving station along with the data characters
D	By varying the frequency shift of the transmitted signal according to a predefined algorithm

42. - E8D02

What spread spectrum communications technique uses a high-speed binary bit stream to shift the phase of an RF carrier?

Select	Answer
A	Binary phase-shift keying
B	Direct sequence
C	Frequency hopping
D	Phase compandored spread spectrum

43. - E9A03

What is the radiation resistance of an antenna?

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

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 resulting design will favor radiation of harmonic energy
B	Ground conductivity will not be accurately modeled
C	The computed feed point impedance may be incorrect
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 vertical angle increases
B	The front-to-back ratio decreases
C	The lobes align more in the direction of the wire
D	The lobes become more perpendicular to the wire

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	Near the center of the vertical radiator
C	As close to the transmitter as possible
D	As low as possible on the vertical radiator

47. - E9E10

Which of these choices is an effective way to match an antenna with a 100-ohm feed point impedance to a 50-ohm coaxial cable feed line?

Select	Answer
A	Connect a 1/4-wavelength open stub of 300-ohm twinlead in parallel with the coaxial feed line where it connects to the antenna
B	Insert a 1/2 wavelength piece of 300-ohm twinlead in series between the antenna terminals and the 50-ohm feed cable
C	Connect a 1/2 wavelength shorted stub of 75-ohm cable in parallel with the 50-ohm cable where it attaches to the antenna
D	Insert a 1/4-wavelength piece of 75-ohm coaxial cable transmission line in series between the antenna terminals and the 50-ohm feed cable

48. - E9F09

What is the approximate physical length of a foam polyethylene dielectric coaxial transmission line that is electrically 1/4 wavelength long at 7.2 MHz?

Select	Answer
A	6.9 meters
B	10.4 meters
C	5.2 meters
D	8.3 meters

49. - E9G03

Which of the following is often determined using a Smith chart?

Select	Answer
A	Satellite azimuth and elevation bearings
B	Beam headings and radiation patterns
C	Impedance and SWR values in transmission lines
D	Trigonometric functions

50. - E9H04

What is an advantage of placing a grounded electrostatic shield around a small loop direction-finding antenna?

Select	Answer
A	It eliminates tracking errors caused by strong out-of-band signals
B	It eliminates unbalanced capacitive coupling to the surroundings, improving the nulls
C	It adds capacitive loading, increasing the bandwidth of the antenna
D	It increases signal strength by providing a better match to the feed line