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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
BUranium Hexafluoride
CMica
DZinc oxide

2. - E1A09

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

SelectAnswer
ADiscontinue forwarding the communication as soon as you become aware of it
BNotify the nearest FCC Field Engineers office
CAll these choices are correct
DNotify the originating station that the communication does not comply with FCC rules

3. - E1B11

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

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

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?

SelectAnswer
AAt least 73 dB below
BAt least 53 dB below
CAt least 43 dB below
DAt least 63 dB below

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 whose licensee has filed a pre-space notification with the FCC's International Bureau
DAny amateur station, subject to the privileges of the class of operator license held by the control operator

6. - E1E01

For which types of out-of-pocket expenses do the Part 97 rules state that VEs and VECs may be reimbursed?

SelectAnswer
APreparing, processing, administering, and coordinating an examination for an amateur radio operator license
BNo expenses are authorized for reimbursement
CProviding amateur operator license examination preparation training materials
DTeaching an amateur operator license examination preparation course

7. - E1F06

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

SelectAnswer
ATo provide additional spectrum for personal use
BTo provide for experimental amateur communications
CTo allow regular operation on Land Mobile channels
DTo provide temporary operation while awaiting normal licensing

8. - E2A02

Which of the following occurs when a satellite is using an inverting linear transponder?

SelectAnswer
AUpper sideband on the uplink becomes lower sideband on the downlink, and vice versa
BSignal position in the band is reversed
CAll these choices are correct
DDoppler shift is reduced because the uplink and downlink shifts are in opposite directions

9. - E2B11

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

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

10. - E2C04

Which of the following frequencies are sometimes used for amateur radio mesh networks?

SelectAnswer
AFrequencies shared with various unlicensed wireless data services
BHF frequencies where digital communications are permitted
CThe 60 meter band channel centered on 5373 kHz
DCable TV channels 41 through 43

11. - E2D07

What digital protocol is used by APRS?

SelectAnswer
AAX.25
BPACTOR
CAMTOR
D802.11

12. - E2E08

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

SelectAnswer
APACTOR
BHellschreiber
CAMTOR
DRTTY

13. - E3A07

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

SelectAnswer
AForests
BUrban areas
CBodies of water
DMountain ranges

14. - E3B04

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

SelectAnswer
AIndependent waves created in the ionosphere that are elliptically polarized
BLong-path and short-path waves
CExtraordinary waves describe rare long-skip propagation compared to ordinary waves, which travel shorter distances
DRefracted rays and reflected waves

15. - E3C13

What type of polarization is best for ground-wave propagation?

SelectAnswer
AElliptical
BHorizontal
CCircular
DVertical

16. - E4A10

Which of the following displays multiple digital signal states simultaneously?

SelectAnswer
AModulation monitor
BBit error rate tester
CNetwork analyzer
DLogic analyzer

17. - E4B11

Which of the following can be measured with a vector network analyzer?

SelectAnswer
AInput impedance
BOutput impedance
CAll these choices are correct
DReflection coefficient

18. - E4C14

What transmit frequency might generate an image response signal in a receiver tuned to 14.300 MHz and that uses a 455 kHz IF frequency?

SelectAnswer
A14.445 MHz
B14.755 MHz
C15.210 MHz
D13.845 MHz

19. - E4D04

Which of the following may reduce or eliminate intermodulation interference in a repeater caused by another transmitter operating in close proximity?

SelectAnswer
AA properly terminated circulator at the output of the repeater's transmitter
BUtilizing a Class D final amplifier
CUtilizing a Class C final amplifier
DA band-pass filter in the feed line between the transmitter and receiver

20. - E4E09

What undesirable effect can occur when using an IF noise blanker?

SelectAnswer
AReceived audio in the speech range might have an echo effect
BFM signals can no longer be demodulated
CNearby signals may appear to be excessively wide even if they meet emission standards
DThe audio frequency bandwidth of the received signal might be compressed

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?

SelectAnswer
A1.78 MHz
B22.36 MHz
C3.56 MHz
D44.72 MHz

22. - E5B03

How is impedance in polar form converted to an equivalent admittance?

SelectAnswer
ATake the reciprocal of the magnitude and change the sign of the angle
BTake the square root of the magnitude and add 180 degrees to the angle
CSquare the magnitude and subtract 90 degrees from the angle
DTake the reciprocal of the angle and change the sign of the magnitude

23. - E5C05

What is the name of the diagram used to show the phase relationship between impedances at a given frequency?

SelectAnswer
AFar field diagram
BNear field diagram
CVenn diagram
DPhasor diagram

24. - E5D12

How many watts are consumed in a circuit having a power factor of 0.2 if the input is 100 VAC at 4 amperes?

SelectAnswer
A2000 watts
B50 watts
C400 watts
D80 watts

25. - E6A12

Why do many MOSFET devices have internally connected Zener diodes on the gates?

SelectAnswer
ATo keep the gate voltage within specifications and prevent the device from overheating
BTo provide a voltage reference for the correct amount of reverse-bias gate voltage
CTo reduce the chance of static damage to the gate
DTo protect the substrate from excessive voltages

26. - E6B08

Which of the following is a Schottky barrier diode?

SelectAnswer
AElectrolytic rectifier
BThermionic emission diode
CMetal-semiconductor junction
DPIN junction

27. - E6C03

What is tri-state logic?

SelectAnswer
ALogic devices that utilize ternary math
BLow-power logic devices designed to operate at 3 volts
CLogic devices with 0, 1, and high-impedance output states
DProprietary logic devices manufactured by Tri-State Devices

28. - E6D02

What is the equivalent circuit of a quartz crystal?

SelectAnswer
AMotional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in series
BMotional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in parallel
CMotional capacitance, motional inductance, and loss resistance in series, all in parallel with a shunt capacitor representing electrode and stray capacitance
DMotional inductance and loss resistance in series, paralleled with motional capacitance and a capacitor representing electrode and stray capacitance

29. - E6E12

Why are DIP through-hole package ICs not typically used at UHF and higher frequencies?

SelectAnswer
AExcessive lead length
BEpoxy coating is conductive above 300 MHz
CUnsuitable for combining analog and digital signals
DToo many pins

30. - E6F08

Why are optoisolators often used in conjunction with solid-state circuits when switching 120 VAC?

SelectAnswer
AOptoisolators provide a low impedance link between a control circuit and a power circuit
BOptoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched
COptoisolators eliminate the effects of reflected light in the control circuit
DOptoisolators provide impedance matching between the control circuit and power circuit

31. - E7A02

What is the function of a decade counter?

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

32. - E7B04

Where on the load line of a Class A common emitter amplifier would bias normally be set?

SelectAnswer
AAt a point where the bias resistor equals the load resistor
BApproximately halfway between saturation and cutoff
CWhere the load line intersects the voltage axis
DAt a point where the load line intersects the zero bias current curve

33. - E7C10

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

SelectAnswer
AA cavity filter
BA DSP filter
CAn L-C filter
DA crystal filter

34. - E7D05

Which of the following types of linear voltage regulator places a constant load on the unregulated voltage source?

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

35. - E7E09

What occurs when an excessive amount of signal energy reaches a mixer circuit?

SelectAnswer
AAutomatic limiting occurs
BMixer blanking occurs
CSpurious mixer products are generated
DA beat frequency is generated

36. - E7F11

What sets the minimum detectable signal level for a direct-sampling SDR receiver in the absence of atmospheric or thermal noise?

SelectAnswer
AReference voltage level and sample width in bits
BMissing codes and jitter
CSample clock phase noise
DData storage transfer rate

37. - E7G11

What absolute voltage gain can be expected from the circuit in Figure E7-3 when R1 is 3300 ohms and RF is 47 kilohms?

SelectAnswer
A0.07
B14
C28
D7

38. - E7H03

How is positive feedback supplied in a Hartley oscillator?

SelectAnswer
AThrough a tapped coil
BThrough a neutralizing capacitor
CThrough a capacitive divider
DThrough link coupling

39. - E8A02

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

SelectAnswer
AHarmonic regeneration
BLevel shifting
CSuccessive approximation
DPhase reversal

40. - E8B10

What is frequency division multiplexing?

SelectAnswer
ATwo or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter
BTwo or more information streams are merged into a baseband, which then modulates the transmitter
CThe transmitted signal is divided into packets of information
DThe transmitted signal jumps from band to band at a predetermined rate

41. - E8C05

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

SelectAnswer
A26 Hz
B13 Hz
C104 Hz
D52 Hz

42. - E8D03

How does the spread spectrum technique of frequency hopping work?

SelectAnswer
AIf interference is detected by the receiver it will signal the transmitter to change frequencies
BIf interference is detected by the receiver it will signal the transmitter to wait until the frequency is clear
CA binary bit stream is used to shift the phase of an RF carrier very rapidly in a pseudorandom sequence
DThe frequency of the transmitted signal is changed very rapidly according to a pseudorandom sequence also used by the receiving station

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
ADistance from the transmitter
BTake-off angle
CThe standing wave ratio
DSoil conductivity

44. - E9B07

How does the total amount of radiation emitted by a directional gain antenna compare with the total amount of radiation emitted from a theoretical isotropic antenna, assuming each is driven by the same amount of power?

SelectAnswer
AThe total amount of radiation from the directional antenna is increased by the gain of the antenna
BThey are the same
CThe radiation from the isotropic antenna is 2.15 dB stronger than that from the directional antenna
DThe total amount of radiation from the directional antenna is stronger by its front-to-back ratio

45. - E9C10

Which of the following describes a Zepp antenna?

SelectAnswer
AA vertical array capable of quickly changing the direction of maximum radiation by changing phasing lines
BAn omni-directional antenna commonly used for satellite communications
CA dipole constructed from zip cord
DAn end-fed dipole antenna

46. - E9D05

What usually occurs if a Yagi antenna is designed solely for maximum forward gain?

SelectAnswer
AThe SWR is reduced
BThe front-to-back ratio increases
CThe frequency response is widened over the whole frequency band
DThe front-to-back ratio decreases

47. - E9E07

What parameter describes the interactions at the load end of a mismatched transmission line?

SelectAnswer
AVelocity factor
BCharacteristic impedance
CDielectric constant
DReflection coefficient

48. - E9F10

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

SelectAnswer
AA capacitive reactance
BZero
CThe same as the characteristic impedance of the line
DAn inductive reactance

49. - E9G03

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

SelectAnswer
AImpedance and SWR values in transmission lines
BBeam headings and radiation patterns
CTrigonometric functions
DSatellite azimuth and elevation bearings

50. - E9H05

What is the main drawback of a small wire-loop antenna for direction finding?

SelectAnswer
AAll these choices are correct
BIt has a bidirectional pattern
CIt is practical for use only on VHF and higher bands
DIt has no clearly defined null

Figure E7-3