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

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1. - E0A03

Over what range of frequencies are the FCC human body RF exposure limits most restrictive?

SelectAnswer
A300 to 3000 MHz
B3 to 30 MHz
C300 kHz to 3 MHz
D30 to 300 MHz

2. - E1A10

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

SelectAnswer
AIts operation must be approved by the master of the ship or the pilot in command of the aircraft
BThe amateur station must have a power supply that is completely independent of the main ship or aircraft power supply
CThe amateur operator must have an FCC Marine or Aircraft endorsement on his or her amateur license
DThe amateur station operator must agree not to transmit when the main radio of the ship or aircraft is in use

3. - E1B11

What does PRB-1 require of regulations affecting amateur radio?

SelectAnswer
AAmateur radio operations must be permitted in any private residence
BReasonable accommodations of amateur radio must be made
CNo limitations may be placed on antenna size or placement
DUse of wireless devices in a vehicle is exempt from regulation

4. - E1C03

How do the control operator responsibilities of a station under automatic control differ from one under local control?

SelectAnswer
AUnder automatic control the control operator is not required to be present at the control point
BUnder automatic control there is no control operator
CUnder local control there is no control operator
DUnder local control a control operator is not required to be present at a control point

5. - E1D08

Which VHF amateur bands have frequencies authorized for space stations?

SelectAnswer
A6 meters and 2 meters
B6 meters, 2 meters, and 1.25 meters
C2 meters and 1.25 meters
D2 meters

6. - E1E12

What must the VE team do with the application form if the examinee does not pass the exam?

SelectAnswer
AReturn the application document to the examinee
BSend the application form to the FCC and inform the FCC of the grade
CMaintain the application form with the VEC's records
DDestroy the application form

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?

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

8. - E2A10

What type of satellite appears to stay in one position in the sky?

SelectAnswer
AGeostationary
BGeomagnetic
CLEO
DHEO

9. - E2B01

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

SelectAnswer
A60
B30
C120
D90

10. - E2C08

Which of the following contacts may be confirmed through the U.S. QSL bureau system?

SelectAnswer
AContacts using tactical call signs
BContacts between a U.S. station and a non-U.S. station
CRepeater contacts between U.S. club members
DSpecial event contacts between stations in the U.S.

11. - E2D08

What type of packet frame is used to transmit APRS beacon data?

SelectAnswer
AAcknowledgement
BUnnumbered Information
CConnect
DDisconnect

12. - E2E02

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

SelectAnswer
AFatal Error Correction
BFirst Error Correction
CForward Error Correction
DFinal Error Correction

13. - E3A09

Which of the following frequency ranges is most suited for meteor scatter communications?

SelectAnswer
A28 MHz - 148 MHz
B10 MHz - 14 MHz
C1.8 MHz - 1.9 MHz
D220 MHz - 450 MHz

14. - E3B09

At what time of year is sporadic E propagation most likely to occur?

SelectAnswer
AAround the equinoxes, especially the fall equinox
BAround the equinoxes, especially the spring equinox
CAround the solstices, especially the winter solstice
DAround the solstices, especially the summer solstice

15. - E3C08

What does the space weather term G5 mean?

SelectAnswer
AModerate solar wind
BVery low solar activity
CWaning sunspot numbers
DAn extreme geomagnetic storm

16. - E4A09

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

SelectAnswer
AAll these choices are correct
BNever use a DC-coupled probe to measure an AC circuit
CNever use a high-impedance probe to measure a low-impedance circuit
DKeep the signal ground connection of the probe as short as possible

17. - E4B10

Which of the following methods measures intermodulation distortion in an SSB transmitter?

SelectAnswer
AModulate the transmitter using two RF signals having harmonically related frequencies and observe the RF output with a logic analyzer
BModulate the transmitter using two RF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
CModulate the transmitter using two AF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
DModulate the transmitter using two AF signals having harmonically related frequencies and observe the RF output with a peak reading wattmeter

18. - E4C03

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

SelectAnswer
ACapture effect
BFrequency discrimination
CCross-modulation interference
DDesensitization

19. - E4D10

What does a third-order intercept level of 40 dBm mean with respect to receiver performance?

SelectAnswer
AThe receiver can tolerate signals up to 40 dB above the noise floor without producing third-order intermodulation products
BSignals less than 40 dBm will not generate audible third-order intermodulation products
CA pair of 40 dBm input signals will theoretically generate a third-order intermodulation product that has the same output amplitude as either of the input signals
DA pair of 1 mW input signals will produce a third-order intermodulation product that is 40 dB stronger than the input signal

20. - E4E10

What might be the cause of a loud roaring or buzzing AC line interference that comes and goes at intervals?

SelectAnswer
AA malfunctioning illuminated advertising display
BArcing contacts in a thermostatically controlled device
CA defective doorbell or doorbell transformer inside a nearby residence
DAll these choices are correct

21. - E5A05

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

SelectAnswer
AMatching bandwidth is increased
BIt has no effect on impedance matching
CMatching bandwidth is decreased
DMatching range is increased

22. - E5B06

What is susceptance?

SelectAnswer
AThe ratio of magnetic field to electric field
BThe magnetic impedance of a circuit
CA measure of the efficiency of a transformer
DThe imaginary part of admittance

23. - E5C08

What coordinate system is often used to display the phase angle of a circuit containing resistance, inductive and/or capacitive reactance?

SelectAnswer
AFaraday grid
BPolar coordinates
CElliptical coordinates
DMaidenhead grid

24. - E5D11

What is the power factor of an RL circuit having a 60-degree phase angle between the voltage and the current?

SelectAnswer
A0.866
B1.414
C1.73
D0.5

25. - E6A09

What is a depletion-mode FET?

SelectAnswer
AAn FET that exhibits a current flow between source and drain when no gate voltage is applied
BAn FET that has no current flow between source and drain when no gate voltage is applied
CAny FET without a channel
DAny FET for which holes are the majority carriers

26. - E6B07

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

SelectAnswer
AExcessive inverse voltage
BInsufficient forward voltage
CExcessive junction temperature
DCharge carrier depletion

27. - E6C07

What best describes a pull-up or pull-down resistor?

SelectAnswer
AA resistor connected to the positive or negative supply line used to establish a voltage when an input or output is an open circuit
BA resistor in a keying circuit used to reduce key clicks
CA resistor that ensures that an oscillator frequency does not drift
DA resistor connected to an op-amp output that prevents signals from exceeding the power supply voltage

28. - E6D12

What is inductor saturation?

SelectAnswer
AThe ability of the inductor's core to store magnetic energy has been exceeded
BThe inductor windings are over-coupled
CAdjacent inductors become over-coupled
DThe inductor's voltage rating is exceeded causing a flashover

29. - E6E10

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

SelectAnswer
AComponents have less parasitic inductance and capacitance
BSmaller circuit area
CAll these choices are correct
DShorter circuit-board traces

30. - E6F09

What is the efficiency of a photovoltaic cell?

SelectAnswer
AThe output RF power divided by the input DC power
BCost per kilowatt-hour generated
CThe open-circuit voltage divided by the short-circuit current under full illumination
DThe relative fraction of light that is converted to current

31. - E7A08

What logical operation does an OR gate perform?

SelectAnswer
AIt only produces logic 0 at its output when all inputs are logic 1
BIt produces logic 1 at its output if all inputs are logic 0
CIt produces logic 1 at its output if any or all inputs are logic 1
DIt produces logic 0 at its output if all inputs are logic 1

32. - E7B11

In Figure E7-1, what is the purpose of R3?

SelectAnswer
AOutput load resistor
BSelf bias
CFixed bias
DEmitter bypass

33. - E7C04

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

SelectAnswer
AIt introduces transconductance to cancel the reactive part of impedance
BReactive currents are dissipated in matched resistances
CIt cancels the reactive part of the impedance and changes the resistive part to a desired value
DIt introduces negative resistance to cancel the resistive part of impedance

34. - E7D04

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

SelectAnswer
AA shunt current source
BA series current source
CA shunt regulator
DA series regulator

35. - E7E04

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

SelectAnswer
ABy using a loop modulator followed by a mixer
BBy using a balanced modulator followed by a filter
CBy driving a product detector with a DSB signal
DBy using a reactance modulator followed by a mixer

36. - E7F14

Which of the following would allow a digital signal processing filter to create a sharper filter response?

SelectAnswer
AComplex phasor representations
BMore taps
CHigher data rate
DDouble-precision math routines

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?

SelectAnswer
A76
B38
C0.03
D1

38. - E7H05

How is positive feedback supplied in a Pierce oscillator?

SelectAnswer
AThrough a tapped coil
BThrough a neutralizing capacitor
CThrough a quartz crystal
DThrough link coupling

39. - E8A08

Why would a direct or flash conversion analog-to-digital converter be useful for a software defined radio?

SelectAnswer
AVery low power consumption decreases frequency drift
BAll these choices are correct
CImmunity to out-of-sequence coding reduces spurious responses
DVery high speed allows digitizing high frequencies

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?

SelectAnswer
A1.67
B0.167
C0.6
D60

41. - E8C07

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

SelectAnswer
A15.36 kHz
B4.8 kHz
C9.6 kHz
D5.76 kHz

42. - E8D04

What is the primary effect of extremely short rise or fall time on a CW signal?

SelectAnswer
AThe generation of RF harmonics
BMore difficult to copy
CLimits data speed
DThe generation of key clicks

43. - E9A11

Which of the following factors determines ground losses for a ground-mounted vertical antenna operating in the 3 MHz to 30 MHz range?

SelectAnswer
ASoil conductivity
BTake-off angle
CThe standing wave ratio
DDistance from the transmitter

44. - E9B03

In the antenna radiation pattern shown in Figure E9-1, what is the front-to-side ratio?

SelectAnswer
A18 dB
B12 dB
C14 dB
D24 dB

45. - E9C14

How does the performance of a horizontally polarized antenna mounted on the side of a hill compare with the same antenna mounted on flat ground?

SelectAnswer
AThe main lobe takeoff angle increases in the downhill direction
BThe main lobe takeoff angle decreases in the downhill direction
CThe horizontal beamwidth increases in the uphill direction
DThe horizontal beamwidth decreases in the downhill direction

46. - E9D03

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

SelectAnswer
AAs low as possible on the vertical radiator
BNear the center of the vertical radiator
CAt a voltage node
DAs close to the transmitter as possible

47. - E9E11

What is the primary purpose of phasing lines when used with an antenna having multiple driven elements?

SelectAnswer
AIt prevents reflected power from traveling back down the feed line and causing harmonic radiation from the transmitter
BIt creates a low-angle radiation pattern
CIt ensures that each driven element operates in concert with the others to create the desired antenna pattern
DIt allows single-band antennas to operate on other bands

48. - E9F11

What impedance does a 1/8-wavelength transmission line present to a generator when the line is open at the far end?

SelectAnswer
AA capacitive reactance
BAn inductive reactance
CThe same as the characteristic impedance of the line
DInfinite

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?

SelectAnswer
APrime axis
BReactance axis
CPolar axis
DImpedance axis

50. - E9H11

What feature of a cardioid pattern antenna makes it useful for direction finding?

SelectAnswer
AA very sharp peak
BA very sharp single null
CHigh radiation angle
DBroadband response

Figure E7-1

Figure E7-3

Figure E9-1

Figure E9-3