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

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1. - E0A10

What toxic material may be present in some electronic components such as high voltage capacitors and transformers?

Select	Answer
A	Polytetrafluoroethylene
B	Polychlorinated biphenyls
C	Polyethylene
D	Polymorphic silicon

2. - E1A08

If a station in a message forwarding system inadvertently forwards a message that is in violation of FCC rules, who is primarily accountable for the rules violation?

Select	Answer
A	The control operator of the packet bulletin board station
B	The control operators of all the stations in the system
C	The control operators of all the stations in the system not authenticating the source from which they accept communications
D	The control operator of the originating station

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 proposal must be submitted to the National Park Service
B	A form FSD-15 must be submitted to the Department of the Interior
C	A letter of intent must be filed with the Environmental Protection Agency
D	An Environmental Assessment must be submitted to the FCC

4. - E1C06

Which of the following is required in order to operate in accordance with CEPT rules in foreign countries where permitted?

Select	Answer
A	You must append "/CEPT" to your call sign
B	The U.S. embassy must approve of your operation
C	You must identify in the official language of the country in which you are operating
D	You must bring a copy of FCC Public Notice DA 16-1048

5. - E1D01

What is the definition of telemetry?

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

6. - E1E06

Who is responsible for the proper conduct and necessary supervision during an amateur operator license examination session?

Select	Answer
A	Each administering VE
B	The FCC
C	The VE session manager
D	The VEC coordinating the session

7. - E1F11

Which of the following best describes one of the standards that must be met by an external RF power amplifier if it is to qualify for a grant of FCC certification?

Select	Answer
A	It must be capable of external RF switching between its input and output networks
B	It must exhibit a gain of 0 dB or less over its full output range
C	It must produce full legal output when driven by not more than 5 watts of mean RF input power
D	It must satisfy the FCC's spurious emission standards when operated at the lesser of 1500 watts or its full output power

8. - E2A05

What do the letters in a satellite's mode designator specify?

Select	Answer
A	The uplink and downlink frequency ranges
B	Power limits for uplink and downlink transmissions
C	The polarization of uplink and downlink signals
D	The location of the ground control station

9. - E2B11

What is the function of the Vertical Interval Signaling (VIS) code sent as part of an SSTV transmission?

Select	Answer
A	To identify the SSTV mode being used
B	To identify the call sign of the station transmitting
C	To provide vertical synchronization
D	To lock the color burst oscillator in color SSTV images

10. - E2C02

Which of the following best describes the term self-spotting? in connection with HF contest operating?

Select	Answer
A	The acceptable practice of manually posting the call signs of stations on a spotting network
B	An automatic method for rapidly zero beating or tuning to a station's frequency before calling that station
C	A manual technique for rapidly zero beating or tuning to a station's frequency before calling that station
D	The often-prohibited practice of posting one's own call sign and frequency on a spotting network

11. - E2D01

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

Select	Answer
A	Hellschreiber
B	APRS
C	WSPR
D	MSK144

12. - E2E12

How do ALE stations establish contact?

Select	Answer
A	ALE radios send a constant tone code to establish a frequency for future use
B	ALE radios activate when they hear their signal echoed by back scatter
C	ALE constantly scans a list of frequencies, activating the radio when the designated call sign is received
D	ALE radios monitor an internet site for the frequency they are being paged on

13. - E3A07

Atmospheric ducts capable of propagating microwave signals often form over what geographic feature?

Select	Answer
A	Bodies of water
B	Forests
C	Urban areas
D	Mountain ranges

14. - E3B05

Which amateur bands typically support long-path propagation?

Select	Answer
A	6 meters to 2 meters
B	Only 160 meters to 40 meters
C	Only 30 meters to 10 meters
D	160 meters to 10 meters

15. - E3C01

What does the radio communication term "ray tracing" describe?

Select	Answer
A	The process in which an electronic display presents a pattern
B	Determining the radiation pattern from an array of antennas
C	Modeling a radio wave's path through the ionosphere
D	Evaluating high voltage sources for x-rays

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 automatically tune your antenna for resonance
B	Antenna analyzers do not need an external RF source
C	Antenna analyzers display a time-varying representation of the modulation envelope
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 ammeter, the full scale reading in amps divided by ohms per volt rating will determine the size of shunt needed
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	When used as an ohmmeter, the reading in ohms divided by the ohms per volt rating will determine the voltage applied to the circuit
D	The full scale reading of the voltmeter multiplied by its ohms per volt rating will indicate the input impedance of the voltmeter

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

19. - E4D01

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

Select	Answer
A	The minimum difference in dB between the levels of two FM signals that will cause one signal to block the other
B	The difference in dB between the noise floor and the third-order intercept point
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. - E4E08

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

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

21. - E5A14

What is the resonant frequency of an RLC circuit if R is 22 ohms, L is 50 microhenries and C is 40 picofarads?

Select	Answer
A	1.78 MHz
B	3.56 MHz
C	22.36 MHz
D	44.72 MHz

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	68.2 degrees with the voltage lagging the current
B	14.0 degrees with the voltage leading the current
C	68.2 degrees with the voltage leading the current
D	14.0 degrees with the voltage lagging 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	Far field diagram
D	Phasor diagram

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	70.7 watts
B	141.4 watts
C	200 watts
D	100 watts

25. - E6A09

What is a depletion-mode FET?

Select	Answer
A	An FET that has no current flow between source and drain when no gate voltage is applied
B	Any FET for which holes are the majority carriers
C	An FET that exhibits a current flow between source and drain when no gate voltage is applied
D	Any FET without a channel

26. - E6B07

What is the failure mechanism when a junction diode fails due to excessive current?

Select	Answer
A	Insufficient forward voltage
B	Charge carrier depletion
C	Excessive inverse voltage
D	Excessive junction temperature

27. - E6C05

What is an advantage of CMOS logic devices over TTL devices?

Select	Answer
A	Immune to damage from static discharge
B	Lower power consumption
C	Differential output capability
D	Lower distortion

28. - E6D11

Which type of core material decreases inductance when inserted into a coil?

Select	Answer
A	Ceramic
B	Powdered iron
C	Brass
D	Ferrite

29. - E6E10

What advantage does surface-mount technology offer at RF compared to using through-hole components?

Select	Answer
A	Shorter circuit-board traces
B	All these choices are correct
C	Components have less parasitic inductance and capacitance
D	Smaller circuit area

30. - E6F05

Which describes an optical shaft encoder?

Select	Answer
A	A digital encryption device often used to encrypt spacecraft control signals
B	A device for generating RTTY signals by means of a rotating light source
C	A device that measures the strength of a beam of light using analog to digital conversion
D	A device that detects rotation of a control by interrupting a light source with a patterned wheel

31. - E7A09

What logical operation is performed by an exclusive NOR gate?

Select	Answer
A	It produces logic 1 at its output if only one input is logic 1
B	It produces logic 0 at its output only if all inputs are logic 0
C	It produces logic 0 at its output if only one input is logic 1
D	It produces logic 1 at its output only if all inputs are logic 1

32. - E7B09

Which of the following describes how the loading and tuning capacitors are to be adjusted when tuning a vacuum tube RF power amplifier that employs a Pi-network output circuit?

Select	Answer
A	The tuning capacitor is set to maximum capacitance and the loading capacitor is adjusted for minimum plate permissible current
B	The loading capacitor is set to maximum capacitance and the tuning capacitor is adjusted for minimum allowable plate current
C	The tuning capacitor is adjusted for minimum plate current, and the loading capacitor is adjusted for maximum permissible plate current
D	The loading capacitor is adjusted to minimum plate current while alternately adjusting the tuning capacitor for maximum allowable plate current

33. - E7C07

Which describes a Pi-L-network used for matching a vacuum tube final amplifier to a 50-ohm unbalanced output?

Select	Answer
A	A matching network in which all components are isolated from ground
B	A Phase Inverter Load network
C	A Pi-network with an additional series inductor on the output
D	A network with only three discrete parts

34. - E7D04

Which of the following types of linear voltage regulator usually make the most efficient use of the primary power source?

Select	Answer
A	A series regulator
B	A shunt regulator
C	A series current source
D	A shunt current source

35. - E7E04

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

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

36. - E7F10

What aspect of receiver analog-to-digital conversion determines the maximum receive bandwidth of a Direct Digital Conversion SDR?

Select	Answer
A	Processor latency
B	Sample width in bits
C	Sample rate
D	Sample clock phase noise

37. - E7G03

What is the typical input impedance of an op-amp?

Select	Answer
A	1000 ohms
B	100 ohms
C	Very low
D	Very high

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

39. - E8A05

What of the following instruments would be the most accurate for measuring the RMS voltage of a complex waveform?

Select	Answer
A	A grid dip meter
B	A true-RMS calculating meter
C	A D'Arsonval meter
D	An absorption wave meter

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	3
B	2000
C	6000
D	1/3

41. - E8C05

What is the approximate bandwidth of a 13-WPM International Morse Code transmission?

Select	Answer
A	104 Hz
B	26 Hz
C	52 Hz
D	13 Hz

42. - E8D06

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

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

43. - E9A01

What is an isotropic antenna?

Select	Answer
A	A grounded antenna used to measure Earth conductivity
B	A spacecraft antenna used to direct signals toward Earth
C	A horizontally polarized antenna used to compare Yagi antennas
D	A theoretical, omnidirectional antenna used as a reference for antenna gain

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	14 dB
D	18 dB

45. - E9C07

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

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

46. - E9D09

What is the function of a loading coil used as part of an HF mobile antenna?

Select	Answer
A	To increase the SWR bandwidth
B	To cancel capacitive reactance
C	To lower the losses
D	To lower the Q

47. - E9E04

What is the purpose of the series capacitor in a gamma-type antenna matching network?

Select	Answer
A	To provide a rejection notch that prevents the radiation of harmonics
B	To transform the antenna impedance to a higher value
C	To cancel the inductive reactance of the matching network
D	To provide DC isolation between the feed line and the antenna

48. - E9F01

What is the velocity factor of a transmission line?

Select	Answer
A	The index of shielding for coaxial cable
B	The ratio of the characteristic impedance of the line to the terminating impedance
C	The velocity of the wave in the transmission line divided by the velocity of light in a vacuum
D	The velocity of the wave in the transmission line multiplied by the velocity of light in a vacuum

49. - E9G03

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

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

50. - E9H10

How can the output voltage of a multiple-turn receiving loop antenna be increased?

Select	Answer
A	By utilizing high impedance wire for the coupling loop
B	By winding adjacent turns in opposing directions
C	By increasing the number of turns and/or the area
D	By reducing the permeability of the loop shield

Figure E9-1