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

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1. - E0A01

What is the primary function of an external earth connection or ground rod?

SelectAnswer
AReduce received noise
BReduce RFI to telephones and home entertainment systems
CLightning protection
DReduce RF current flow between pieces of equipment

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

3. - E1B12

What must the control operator of a repeater operating in the 70 cm band do if a radiolocation system experiences interference from that repeater?

SelectAnswer
ACease operation or make changes to the repeater to mitigate the interference
BReduce the repeater antenna HAAT (Height Above Average Terrain)
CFile an FAA NOTAM (Notice to Airmen) with the repeater system's ERP, call sign, and six-character grid locator
DAll these choices are correct

4. - E1C01

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

SelectAnswer
A170 Hz
B1.5 kHz
C2.8 kHz
D60 Hz

5. - E1D02

Which of the following may transmit special codes intended to obscure the meaning of messages?

SelectAnswer
AAuxiliary relay links carrying repeater audio
BBinary control characters
CTelecommand signals from a space telecommand station
DData containing personal information

6. - E1E03

What is a Volunteer Examiner Coordinator?

SelectAnswer
AThe person who has entered into an agreement with the FCC to be the VE session manager
BA person who has volunteered to prepare amateur operator license examinations
CAn organization that has entered into an agreement with the FCC to coordinate, prepare, and administer amateur operator license examinations
DA person who has volunteered to administer amateur operator license examinations

7. - E1F05

Amateur stations may not transmit in which of the following frequency segments if they are located in the contiguous 48 states and north of Line A?

SelectAnswer
A222 MHz - 223 MHz
B53 MHz - 54 MHz
C420 MHz - 430 MHz
D440 MHz - 450 MHz

8. - E2A01

What is the direction of an ascending pass for an amateur satellite?

SelectAnswer
AFrom east to west
BFrom west to east
CFrom south to north
DFrom north to south

9. - E2B09

What hardware, other than a receiver with SSB capability and a suitable computer, is needed to decode SSTV using Digital Radio Mondiale (DRM)?

SelectAnswer
AA special notch filter to remove synchronization pulses
BNo other hardware is needed
CA special IF converter
DA special front end limiter

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. - E2D07

What digital protocol is used by APRS?

SelectAnswer
AAMTOR
BPACTOR
C802.11
DAX.25

12. - E2E06

What is the most common data rate used for HF packet?

SelectAnswer
A110 baud
B1200 baud
C48 baud
D300 baud

13. - E3A05

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

SelectAnswer
ASprites and jets
BWarm and cold fronts
CGrayline
DLightning discharges

14. - E3B05

Which amateur bands typically support long-path propagation?

SelectAnswer
AOnly 160 meters to 40 meters
B160 meters to 10 meters
C6 meters to 2 meters
DOnly 30 meters to 10 meters

15. - E3C09

How does the intensity of an X3 flare compare to that of an X2 flare?

SelectAnswer
A10 percent greater
BTwice as great
CFour times as great
D50 percent greater

16. - E4A01

Which of the following limits the highest frequency signal that can be accurately displayed on a digital oscilloscope?

SelectAnswer
AQ of the circuit
BSampling rate of the analog-to-digital converter
CAmount of memory
DAll these choices are correct

17. - E4B02

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

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

18. - E4C15

What is reciprocal mixing?

SelectAnswer
ATwo out-of-band signals mixing to generate an in-band spurious signal
BIn-phase signals cancelling in a mixer resulting in loss of receiver sensitivity
CLocal oscillator phase noise mixing with adjacent strong signals to create interference to desired signals
DTwo digital signals combining from alternate time slots

19. - E4D02

Which of the following describes problems caused by poor dynamic range in a receiver?

SelectAnswer
ASpurious signals caused by cross-modulation and desensitization from strong adjacent signals
BOscillator instability and severe audio distortion of all but the strongest received signals
COscillator instability requiring frequent retuning and loss of ability to recover the opposite sideband
DCross-modulation of the desired signal and insufficient audio power to operate the speaker

20. - E4E07

Which of the following can cause shielded cables to radiate or receive interference?

SelectAnswer
ATying all ground connections to a common point resulting in differential-mode currents in the shield
BCommon-mode currents on the shield and conductors
CUse of braided shielding material
DLow inductance ground connections at both ends of the shield

21. - E5A10

How is the Q of an RLC series resonant circuit calculated?

SelectAnswer
AReactance of either the inductance or capacitance multiplied by the resistance
BReactance of either the inductance or capacitance divided by the resistance
CReactance of the inductance multiplied by the reactance of the capacitance
DResistance divided by the reactance of either the inductance or capacitance

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
A76 degrees with the voltage leading the current
B14 degrees with the voltage lagging the current
C14 degrees with the voltage leading the current
D76 degrees with the voltage lagging the current

23. - E5C06

What does the impedance 50-j25 represent?

SelectAnswer
A25 ohms resistance in series with 50 ohms inductive reactance
B50 ohms resistance in series with 25 ohms inductive reactance
C50 ohms resistance in series with 25 ohms capacitive reactance
D25 ohms resistance in series with 50 ohms capacitive reactance

24. - E5D08

How many watts are consumed in a circuit having a power factor of 0.6 if the input is 200VAC at 5 amperes?

SelectAnswer
A1000 watts
B200 watts
C1600 watts
D600 watts

25. - E6A11

In Figure E6-1, what is the schematic symbol for a P-channel junction FET?

SelectAnswer
A1
B3
C2
D6

26. - E6B02

What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

SelectAnswer
ALess forward voltage drop
BLonger carrier retention time
CMuch higher reverse voltage breakdown
DMore constant reverse avalanche 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
BAll these choices are correct
CIt is immune to electrostatic damage
DIts simplicity results in much less expensive devices than standard CMOS

28. - E6D03

Which of the following is an aspect of the piezoelectric effect?

SelectAnswer
AMechanical deformation of material by the application of a magnetic field
BIncreased conductivity in the presence of light
CMechanical deformation of material by the application of a voltage
DGeneration of electrical energy in the presence of light

29. - E6E08

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

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

30. - E6F02

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

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

31. - E7A10

What is a truth table?

SelectAnswer
AA table of logic symbols that indicate the high logic states of an op-amp
BA diagram showing logic states when the digital device output is true
CA table of logic symbols that indicate the logic states of an op-amp
DA list of inputs and corresponding outputs for a digital device

32. - E7B13

Which of the following describes an emitter follower (or common collector) amplifier?

SelectAnswer
AAn amplifier with a low impedance output that follows the base input voltage
BA two-transistor amplifier with the emitters sharing a common bias resistor
CAn OR circuit with only one emitter used for output
DA differential amplifier with both inputs fed to the emitter of the input transistor

33. - E7C01

How are the capacitors and inductors of a low-pass filter Pi-network arranged between the network's input and output?

SelectAnswer
ATwo inductors are in series between the input and output, and a capacitor is connected between the two inductors and ground
BAn inductor is connected between the input and ground, another inductor is connected between the output and ground, and a capacitor is connected between the input and output
CTwo capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground
DA capacitor is connected between the input and ground, another capacitor is connected between the output and ground, and an inductor is connected between input and output

34. - E7D15

What is the purpose of a step-start circuit in a high-voltage power supply?

SelectAnswer
ATo allow for remote control of the power supply
BTo provide a dual-voltage output for reduced power applications
CTo compensate for variations of the incoming line voltage
DTo allow the filter capacitors to charge gradually

35. - E7E05

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

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

36. - E7F02

What kind of digital signal processing audio filter is used to remove unwanted noise from a received SSB signal?

SelectAnswer
AA crystal-lattice filter
BAn adaptive filter
CA phase-inverting filter
DA Hilbert-transform filter

37. - E7G03

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

SelectAnswer
A100 ohms
BVery high
C1000 ohms
DVery low

38. - E7H06

Which of the following oscillator circuits are commonly used in VFOs?

SelectAnswer
AColpitts and Hartley
BNegative feedback and balanced feedback
CPierce and Zener
DArmstrong and deForest

39. - E8A07

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

SelectAnswer
ASpeech characteristics
BThe frequency of the modulating signal
CAmplifier gain
DThe degree of carrier suppression

40. - E8B10

What is frequency division multiplexing?

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

41. - E8C04

What technique minimizes the bandwidth of a PSK31 signal?

SelectAnswer
AReed-Solomon character encoding
BUse of sinusoidal data pulses
CUse of trapezoidal data pulses
DZero-sum character encoding

42. - E8D11

What is one advantage of using ASCII code for data communications?

SelectAnswer
AIt uses one character as a shift code to send numeric and special characters
BIt is possible to transmit both upper and lower case text
CIt contains fewer information bits per character than any other code
DIt includes built-in error correction features

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
AThe standing wave ratio
BSoil conductivity
CTake-off angle
DDistance from the transmitter

44. - E9B01

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

SelectAnswer
A50 degrees
B25 degrees
C75 degrees
D30 degrees

45. - E9C03

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed in phase?

SelectAnswer
ACardioid
BA Figure-8 broadside to the axis of the array
COmni-directional
DA Figure-8 end-fire along the axis of the array

46. - E9D01

How much does the gain of an ideal parabolic dish antenna change when the operating frequency is doubled?

SelectAnswer
A3 dB
B2 dB
C6 dB
D4 dB

47. - E9E07

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

SelectAnswer
AReflection coefficient
BCharacteristic impedance
CDielectric constant
DVelocity factor

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. - E9G11

How are the wavelength scales on a Smith chart calibrated?

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

50. - E9H01

When constructing a Beverage antenna, which of the following factors should be included in the design to achieve good performance at the desired frequency?

SelectAnswer
AIts overall length must not exceed 1/4 wavelength
BIt should be one or more wavelengths long
CIt must be mounted more than 1 wavelength above ground
DIt should be configured as a four-sided loop

Figure E6-1

Figure E9-1