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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
ABeryllium Oxide
BMica
CZinc oxide
DUranium Hexafluoride

2. - E1A02

When using a transceiver that displays the carrier frequency of phone signals, which of the following displayed frequencies represents the lowest frequency at which a properly adjusted LSB emission will be totally within the band?

SelectAnswer
A3 kHz above the lower band edge
BThe exact lower band edge
C300 Hz above the lower band edge
D1 kHz above the lower band edge

3. - E1B10

What frequencies are authorized to an amateur station operating under RACES rules?

SelectAnswer
ASpecific segments in the amateur service MF, HF, VHF and UHF bands
BAll amateur service frequencies authorized to the control operator
CSpecific local government channels
DMilitary Auxiliary Radio System (MARS) channels

4. - E1C06

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

SelectAnswer
AYou must append "/CEPT" to your call sign
BYou must identify in the official language of the country in which you are operating
CYou must bring a copy of FCC Public Notice DA 16-1048
DThe U.S. embassy must approve of your operation

5. - E1D11

Which amateur stations are eligible to operate as Earth stations?

SelectAnswer
AOnly those of Amateur Extra Class operators
BOnly those of General, Advanced or Amateur Extra Class operators
CAny amateur station, subject to the privileges of the class of operator license held by the control operator
DAny amateur station whose licensee has filed a pre-space notification with the FCC's International Bureau

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
AAll these choices are correct
BThree VEs must certify that the examinee is qualified for the license grant and that they have complied with the administering VE requirements
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 Amateur Extra Class operators
BOnly Technician, General, Advanced or Amateur Extra Class operators
CAny licensed amateur operator
DOnly General, Advanced or Amateur Extra Class operators

8. - E2A09

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

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

9. - E2B08

What technique allows commercial analog TV receivers to be used for fast-scan TV operations on the 70 cm band?

SelectAnswer
AUsing converted satellite TV dishes
BTransmitting on channels shared with cable TV
CTransmitting on the abandoned TV channel 2
DUsing USB and demodulating the signal with a computer sound card

10. - E2C06

During a VHF/UHF contest, in which band segment would you expect to find the highest level of SSB or CW activity?

SelectAnswer
AIn the middle of each band, usually on the national calling frequency
BIn the weak signal segment of the band, with most of the activity near the calling frequency
CAt the top of each band, usually in a segment reserved for contests
DIn the middle of the band, usually 25 kHz above the national calling frequency

11. - E2D08

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

SelectAnswer
AUnnumbered Information
BConnect
CAcknowledgement
DDisconnect

12. - E2E08

Which of the following HF digital modes can be used to transfer binary files?

SelectAnswer
AHellschreiber
BPACTOR
CRTTY
DAMTOR

13. - E3A05

Tropospheric propagation of microwave signals often occurs in association with what phenomenon?

SelectAnswer
AWarm and cold fronts
BGrayline
CSprites and jets
DLightning discharges

14. - E3B02

What is the approximate maximum range for signals using transequatorial propagation?

SelectAnswer
A7500 miles
B2500 miles
C1000 miles
D5000 miles

15. - E3C11

What does VOACAP software model?

SelectAnswer
AAC voltage and impedance
BAC current and impedance
CVHF radio propagation
DHF propagation

16. - E4A11

How should an antenna analyzer be connected when measuring antenna resonance and feed point impedance?

SelectAnswer
AConnect the antenna feed line directly to the analyzer's connector
BLoosely couple the antenna and a dummy load to the analyzer
CLoosely couple the analyzer near the antenna base
DConnect the analyzer via a high-impedance transformer to the antenna

17. - E4B06

How much power is being absorbed by the load when a directional power meter connected between a transmitter and a terminating load reads 100 watts forward power and 25 watts reflected power?

SelectAnswer
A100 watts
B75 watts
C25 watts
D125 watts

18. - E4C01

What is an effect of excessive phase noise in a receiver's local oscillator?

SelectAnswer
AIt can affect the receiver's frequency calibration
BIt limits the receiver's ability to receive strong signals
CIt can combine with strong signals on nearby frequencies to generate interference
DIt decreases receiver third-order intercept point

19. - E4D10

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

SelectAnswer
ASignals less than 40 dBm will not generate audible third-order intermodulation products
BA 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
CThe receiver can tolerate signals up to 40 dB above the noise floor without producing third-order intermodulation products
DA pair of 1 mW input signals will produce a third-order intermodulation product that is 40 dB stronger than the input signal

20. - E4E06

What is one type of electrical interference that might be caused by a nearby personal computer?

SelectAnswer
AThe appearance of unstable modulated or unmodulated signals at specific frequencies
BA clicking noise at intervals of a few seconds
CA whining type noise that continually pulses off and on
DA loud AC hum in the audio output of your station receiver

21. - E5A06

What is the magnitude of the circulating current within the components of a parallel LC circuit at resonance?

SelectAnswer
AIt equals 2 multiplied by pi, multiplied by frequency, multiplied by inductance
BIt equals 1 divided by the quantity 2 times pi, multiplied by the square root of inductance L multiplied by capacitance C
CIt is at a minimum
DIt is at a maximum

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. - E5C04

What coordinate system is often used to display the resistive, inductive, and/or capacitive reactance components of impedance?

SelectAnswer
AMaidenhead grid
BFaraday grid
CRectangular coordinates
DElliptical coordinates

24. - E5D07

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

SelectAnswer
A1.42 mW
B355 W
C252 W
D704 W

25. - E6A02

Which of the following semiconductor materials contains excess free electrons?

SelectAnswer
AInsulated gate
BBipolar
CP-type
DN-type

26. - E6B01

What is the most useful characteristic of a Zener diode?

SelectAnswer
AA negative resistance region
BA constant voltage drop under conditions of varying current
CAn internal capacitance that varies with the applied voltage
DA constant current drop under conditions of varying voltage

27. - E6C04

Which of the following is an advantage of BiCMOS logic?

SelectAnswer
AIt has the high input impedance of CMOS and the low output impedance of bipolar transistors
BIt is immune to electrostatic damage
CAll these choices are correct
DIts simplicity results in much less expensive devices than standard CMOS

28. - E6D07

What is current in the primary winding of a transformer called if no load is attached to the secondary?

SelectAnswer
AExcitation current
BMagnetizing current
CDirect current
DStabilizing current

29. - E6E08

How is power supplied to the most common type of MMIC?

SelectAnswer
AThrough a resistor and/or RF choke connected to the amplifier output lead
BThrough a capacitor and RF choke connected to the amplifier input lead
CDirectly to the bias voltage (VCC IN) lead
DMMICs require no operating bias

30. - E6F02

What happens to the conductivity of a photoconductive material when light shines on it?

SelectAnswer
AIt increases
BIt becomes unstable
CIt stays the same
DIt decreases

31. - E7A02

What is the function of a decade counter?

SelectAnswer
AIt produces one output pulse for every 10 input pulses
BIt decodes a binary number for display on a seven-segment LED display
CIt produces 10 output pulses for every input pulse
DIt decodes a decimal number for display on a seven-segment LED display

32. - E7B02

What is a Class D amplifier?

SelectAnswer
AA low power amplifier that uses a differential amplifier for improved linearity
BA type of amplifier that uses switching technology to achieve high efficiency
CAn amplifier that uses drift-mode FETs for high efficiency
DA frequency doubling amplifier

33. - E7C03

What advantage does a series-L Pi-L-network have over a series-L Pi-network for impedance matching between the final amplifier of a vacuum-tube transmitter and an antenna?

SelectAnswer
AGreater harmonic suppression
BDoes not require a capacitor
CGreater transformation range
DHigher efficiency

34. - E7D04

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

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

35. - E7E05

What circuit is added to an FM transmitter to boost the higher audio frequencies?

SelectAnswer
AA heterodyne enhancer
BA pre-emphasis network
CA heterodyne suppressor
DA de-emphasis network

36. - E7F06

What is the minimum number of bits required for an analog-to-digital converter to sample a signal with a range of 1 volt at a resolution of 1 millivolt?

SelectAnswer
A6 bits
B10 bits
C4 bits
D8 bits

37. - E7G07

What magnitude of voltage gain can be expected from the circuit in Figure E73 when R1 is 10 ohms and RF is 470 ohms?

SelectAnswer
A94
B47
C0.21
D24

38. - E7H15

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

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

39. - E8A07

What determines the PEP-to-average power ratio of a single-sideband phone signal?

SelectAnswer
ASpeech characteristics
BAmplifier gain
CThe frequency of the modulating signal
DThe degree of carrier suppression

40. - E8B07

Orthogonal Frequency Division Multiplexing is a technique used for which type of amateur communication?

SelectAnswer
AHigh-speed digital modes
BOFDM signals are not allowed on amateur bands
CExtremely low-power contacts
DEME

41. - E8C10

How may data rate be increased without increasing bandwidth?

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

42. - E8D05

What is the most common method of reducing key clicks?

SelectAnswer
AIncrease keying waveform rise and fall times
BLow-pass filters at the transmitter output
CHigh-pass filters at the transmitter output
DReduce keying waveform rise and fall times

43. - E9A10

Which of the following improves the efficiency of a ground-mounted quarter-wave vertical antenna?

SelectAnswer
AAll these choices are correct
BInstalling a radial system
CShortening the radiating element
DIsolating the coax shield from ground

44. - E9B01

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

SelectAnswer
A30 degrees
B75 degrees
C25 degrees
D50 degrees

45. - E9C11

How is the far-field elevation pattern of a vertically polarized antenna affected by being mounted over seawater versus soil?

SelectAnswer
AAdditional higher vertical angle lobes will appear
BThe low-angle radiation decreases
CThe low-angle radiation increases
DFewer vertical angle lobes will be present

46. - E9D06

What happens to the SWR bandwidth when one or more loading coils are used to resonate an electrically short antenna?

SelectAnswer
AIt is unchanged if the loading coil is located at the feed point
BIt is increased
CIt is decreased
DIt is unchanged if the loading coil is located at a voltage maximum point

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 stub match
BThe epsilon match
CThe gamma match
DThe delta match

48. - E9F03

Why is the physical length of a coaxial cable transmission line shorter than its electrical length?

SelectAnswer
AThe surge impedance is higher in a parallel feed line
BElectrical signals move more slowly in a coaxial cable than in air
CThe characteristic impedance is higher in a parallel feed line
DSkin effect is less pronounced in the coaxial cable

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
AImpedance axis
BReactance axis
CPolar axis
DPrime axis

50. - E9H02

Which is generally true for low band (160 meter and 80 meter) receiving antennas?

SelectAnswer
AAll these choices are correct
BAtmospheric noise is so high that gain over a dipole is not important
CThey must be erected at least 1/2 wavelength above the ground to attain good directivity
DLow loss coax transmission line is essential for good performance

Figure E9-1

Figure E9-3