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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?

SelectAnswer
AMica
BUranium Hexafluoride
CZinc oxide
DBeryllium Oxide

2. - E1A01

Which of the following carrier frequencies is illegal for LSB AFSK emissions on the 17 meter band RTTY and data segment of 18.068 to 18.110 MHz?

SelectAnswer
A18.068 MHz
B18.100 MHz
C18.107 MHz
D18.110 MHz

3. - E1B09

Which amateur stations may be operated under RACES rules?

SelectAnswer
AOnly those club stations licensed to Amateur Extra Class operators
BAny FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)
CAny FCC-licensed amateur station except a Technician Class
DAny FCC-licensed amateur station certified by the responsible civil defense organization for the area served

4. - E1C01

What is the maximum bandwidth for a data emission on 60 meters?

SelectAnswer
A170 Hz
B2.8 kHz
C1.5 kHz
D60 Hz

5. - E1D04

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

SelectAnswer
AThe station's six-character Maidenhead grid locator
BThe output power of the balloon transmitter
CAll these choices are correct
DCall sign

6. - E1E11

What must the VE team do if an examinee scores a passing grade on all examination elements needed for an upgrade or new license?

SelectAnswer
AThree VEs must certify that the examinee is qualified for the license grant and that they have complied with the administering VE requirements
BAll these choices are correct
CPhotocopy all examination documents and forward them to the FCC for processing
DIssue the examinee the new or upgrade license

7. - E1F10

Who may be the control operator of an auxiliary station?

SelectAnswer
AOnly Technician, General, Advanced or Amateur Extra Class operators
BAny licensed amateur operator
COnly Amateur Extra Class operators
DOnly General, Advanced or Amateur Extra Class operators

8. - E2A09

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

SelectAnswer
AWhich sideband to use
BThe 2 meter and 70 centimeter bands
CThe 23 centimeter and 13 centimeter bands
DFM and Digital Store-and-Forward systems

9. - E2B11

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

SelectAnswer
ATo identify the call sign of the station transmitting
BTo provide vertical synchronization
CTo identify the SSTV mode being used
DTo lock the color burst oscillator in color SSTV images

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.?

SelectAnswer
A/ followed by the ARRL Section of the remote station
B/R# where # is the district of the remote station
CNo additional indicator is required
D/ followed by the USPS two-letter abbreviation for the state in which the remote station is located

11. - E2D05

What is one advantage of the JT65 mode?

SelectAnswer
APermits fast-scan TV transmissions over narrow bandwidth
BEasily copied by ear if necessary
CUses only a 65 Hz bandwidth
DThe ability to decode signals which have a very low signal-to-noise ratio

12. - E2E09

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

SelectAnswer
APSK31
BRTTY
CMT63
DPACTOR

13. - E3A10

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

SelectAnswer
AThe jet stream
BDust devil
CTemperature inversion
DWind shear

14. - E3B04

What is meant by the terms "extraordinary" and "ordinary" waves?

SelectAnswer
ALong-path and short-path waves
BRefracted rays and reflected waves
CIndependent waves created in the ionosphere that are elliptically polarized
DExtraordinary waves describe rare long-skip propagation compared to ordinary waves, which travel shorter distances

15. - E3C02

What is indicated by a rising A or K index?

SelectAnswer
ADecreasing disruption of the geomagnetic field
BIncreasing disruption of the geomagnetic field
CHigher levels of solar UV radiation
DAn increase in the critical frequency

16. - E4A08

Which of the following measures SWR?

SelectAnswer
AA Q meter
BA spectrum analyzer
CAn antenna analyzer
DAn ohmmeter

17. - E4B02

What is the significance of voltmeter sensitivity expressed in ohms per volt?

SelectAnswer
AWhen used as an ohmmeter, the reading in ohms divided by the ohms per volt rating will determine the voltage applied to the circuit
BWhen used as an ammeter, the full scale reading in amps divided by ohms per volt rating will determine the size of shunt needed
CWhen 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
DThe full scale reading of the voltmeter multiplied by its ohms per volt rating will indicate the input impedance of the voltmeter

18. - E4C02

Which of the following receiver circuits can be effective in eliminating interference from strong out-of-band signals?

SelectAnswer
AA properly adjusted product detector
BA front-end filter or pre-selector
CA notch filter
DA narrow IF filter

19. - E4D11

Why are odd-order intermodulation products, created within a receiver, of particular interest compared to other products?

SelectAnswer
AOdd-order products overload the IF filters
BOdd-order products are an indication of poor image rejection
COdd-order products of two signals in the band of interest are also likely to be within the band
DOdd-order intermodulation produces three products for every input signal within the band of interest

20. - E4E01

What problem can occur when using an automatic notch filter (ANF) to remove interfering carriers while receiving CW signals?

SelectAnswer
ARinging in the DSP filter will completely remove the spaces between the CW characters
BAny nearby signal passing through the DSP system will overwhelm the desired signal
CRemoval of the CW signal as well as the interfering carrier
DReceived CW signals will appear to be modulated at the DSP clock frequency

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?

SelectAnswer
A47.3 kHz
B315.6 Hz
C157.8 Hz
D23.67 kHz

22. - E5B11

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 25 ohms, R is 100 ohms, and XL is 50 ohms?

SelectAnswer
A14 degrees with the voltage leading the current
B14 degrees with the voltage lagging the current
C76 degrees with the voltage lagging the current
D76 degrees with the voltage leading the current

23. - E5C07

Where is the impedance of a pure resistance plotted on rectangular coordinates?

SelectAnswer
AOn the horizontal axis
BOn a horizontal line, offset vertically above the horizontal axis
COn the vertical axis
DOn a line through the origin, slanted at 45 degrees

24. - E5D09

What happens to reactive power in an AC circuit that has both ideal inductors and ideal capacitors?

SelectAnswer
AIt is dissipated as kinetic energy in the circuit
BIt is repeatedly exchanged between the associated magnetic and electric fields, but is not dissipated
CIt is dissipated in the formation of inductive and capacitive fields
DIt is dissipated as heat in the circuit

25. - E6A01

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

SelectAnswer
AIn high-current rectifier circuits
BIn high-power audio circuits
CIn microwave circuits
DIn very low-frequency RF circuits

26. - E6B10

In Figure E6-2, what is the schematic symbol for a light-emitting diode?

SelectAnswer
A7
B5
C6
D1

27. - E6C11

In Figure E6-3, what is the schematic symbol for the NOT operation (inverter)?

SelectAnswer
A4
B6
C5
D2

28. - E6D09

What devices are commonly used as VHF and UHF parasitic suppressors at the input and output terminals of a transistor HF amplifier?

SelectAnswer
ASteel-core toroids
BElectrolytic capacitors
CButterworth filters
DFerrite beads

29. - E6E10

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

SelectAnswer
AAll these choices are correct
BShorter circuit-board traces
CSmaller circuit area
DComponents have less parasitic inductance and capacitance

30. - E6F06

Which of these materials is most commonly used to create photoconductive devices?

SelectAnswer
AA heavy metal
BA liquid semiconductor
CAn ordinary metal
DA crystalline semiconductor

31. - E7A06

What is a characteristic of a monostable multivibrator?

SelectAnswer
AIt maintains a constant output voltage, regardless of variations in the input voltage
BIt produces a continuous square wave oscillating between 1 and 0
CIt switches momentarily to the opposite binary state and then returns to its original state after a set time
DIt stores one bit of data in either a 0 or 1 state

32. - E7B06

Which of the following amplifier types reduces even-order harmonics?

SelectAnswer
AClass AB
BPush-push
CClass C
DPush-pull

33. - E7C10

Which of the following filters would be the best choice for use in a 2 meter band repeater duplexer?

SelectAnswer
AAn L-C filter
BA cavity filter
CA DSP filter
DA crystal filter

34. - E7D01

How does a linear electronic voltage regulator work?

SelectAnswer
AThe conduction of a control element is varied to maintain a constant output voltage
BThe control element duty cycle is proportional to the line or load conditions
CIt eliminates the need for a pass transistor
DIt has a ramp voltage as its output

35. - E7E01

Which of the following can be used to generate FM phone emissions?

SelectAnswer
AA reactance modulator on the oscillator
BA balanced modulator on the oscillator
CA balanced modulator on the audio amplifier
DA reactance modulator on the final amplifier

36. - E7F09

Why is an anti-aliasing digital filter required in a digital decimator?

SelectAnswer
AIt removes low-frequency signal components to eliminate the need for DC restoration
BIt notches out the sampling frequency to avoid sampling errors
CIt peaks the response of the decimator, improving bandwidth
DIt removes high-frequency signal components that would otherwise be reproduced as lower frequency components

37. - E7G06

What is the gain-bandwidth of an operational amplifier?

SelectAnswer
AThe maximum frequency for a filter circuit using that type of amplifier
BThe gain of the amplifier at a filter's cutoff frequency
CThe frequency at which the open-loop gain of the amplifier equals one
DThe frequency at which the amplifier's offset voltage is zero

38. - E7H15

Which of these functions can be performed by a phase-locked loop?

SelectAnswer
AWide-band AF and RF power amplification
BPhotovoltaic conversion, optical coupling
CComparison of two digital input signals, digital pulse counter
DFrequency synthesis, FM demodulation

39. - E8A02

Which of the following is a type of analog-to-digital conversion?

SelectAnswer
APhase reversal
BHarmonic regeneration
CSuccessive approximation
DLevel shifting

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?

SelectAnswer
A1/3
B6000
C2000
D3

41. - E8C10

How may data rate be increased without increasing bandwidth?

SelectAnswer
AIt is impossible
BUsing forward error correction
CIncreasing analog-to-digital conversion resolution
DUsing a more efficient digital code

42. - E8D10

What are some of the differences between the Baudot digital code and ASCII?

SelectAnswer
ABaudot uses 6 data bits per character, ASCII uses 7 or 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes
BBaudot uses 5 data bits per character, ASCII uses 7 or 8; Baudot uses 2 characters as letters/figures shift codes, ASCII has no letters/figures shift code
CBaudot uses 4 data bits per character, ASCII uses 7 or 8; Baudot uses 1 character as a letters/figures shift code, ASCII has no letters/figures code
DBaudot uses 7 data bits per character, ASCII uses 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes

43. - E9A01

What is an isotropic antenna?

SelectAnswer
AA horizontally polarized antenna used to compare Yagi antennas
BA spacecraft antenna used to direct signals toward Earth
CA theoretical, omnidirectional antenna used as a reference for antenna gain
DA grounded antenna used to measure Earth conductivity

44. - E9B01

In the antenna radiation pattern shown in Figure E9-1, what is the beamwidth?

SelectAnswer
A75 degrees
B50 degrees
C30 degrees
D25 degrees

45. - E9C06

What is the effect of adding a terminating resistor to a rhombic antenna?

SelectAnswer
AIt changes the radiation pattern from bidirectional to unidirectional
BIt changes the radiation pattern from horizontal to vertical polarization
CIt reflects the standing waves on the antenna elements back to the transmitter
DIt decreases the ground loss

46. - E9D08

What happens as the Q of an antenna increases?

SelectAnswer
ASWR bandwidth increases
BMore common-mode current is present on the feed line
CGain is reduced
DSWR bandwidth decreases

47. - E9E02

What is the name of an antenna matching system that matches an unbalanced feed line to an antenna by feeding the driven element both at the center of the element and at a fraction of a wavelength to one side of center?

SelectAnswer
AThe gamma match
BThe delta match
CThe stub match
DThe epsilon match

48. - E9F12

What impedance does a 1/4-wavelength transmission line present to a generator when the line is open at the far end?

SelectAnswer
AThe same as the characteristic impedance of the line
BVery low impedance
CThe same as the input impedance to the generator
DVery high impedance

49. - E9G11

How are the wavelength scales on a Smith chart calibrated?

SelectAnswer
AIn fractions of transmission line electrical frequency
BIn fractions of antenna electrical wavelength
CIn fractions of antenna electrical frequency
DIn fractions of transmission line electrical wavelength

50. - E9H09

What is a Pennant antenna?

SelectAnswer
AA four-element, high-gain vertical array invented by George Pennant
BA small, vertically oriented receiving antenna consisting of a triangular loop terminated in approximately 900 ohms
CA form of rhombic antenna terminated in a variable capacitor to provide frequency diversity
DA stealth antenna built to look like a flagpole

Figure E6-2

Figure E6-3

Figure E9-1