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

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1. - E0A10

What toxic material may be present in some electronic components such as high voltage capacitors and transformers?

SelectAnswer
APolychlorinated biphenyls
BPolymorphic silicon
CPolytetrafluoroethylene
DPolyethylene

2. - E1A10

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

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

3. - E1B02

Which of the following is an acceptable bandwidth for Digital Radio Mondiale (DRM) based voice or SSTV digital transmissions made on the HF amateur bands?

SelectAnswer
A3 kHz
B10 kHz
C15 kHz
D20 kHz

4. - E1C04

What is meant by IARP?

SelectAnswer
AAn international amateur radio permit that allows U.S. amateurs to operate in certain countries of the Americas
BA forecast of intermittent aurora radio propagation
CAn indication of increased antenna reflected power
DThe internal amateur radio practices policy of the FCC

5. - E1D08

Which VHF amateur bands have frequencies authorized for space stations?

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

6. - E1E07

What should a VE do if a candidate fails to comply with the examiner's instructions during an amateur operator license examination?

SelectAnswer
AImmediately terminate the candidate's examination
BAllow the candidate to complete the examination, but invalidate the results
CWarn the candidate that continued failure to comply will result in termination of the examination
DImmediately terminate everyone's examination and close the session

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
A53 MHz - 54 MHz
B440 MHz - 450 MHz
C420 MHz - 430 MHz
D222 MHz - 223 MHz

8. - E2A01

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

SelectAnswer
AFrom west to east
BFrom south to north
CFrom east to west
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
ANo other hardware is needed
BA special notch filter to remove synchronization pulses
CA special front end limiter
DA special IF converter

10. - E2C04

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

SelectAnswer
ACable TV channels 41 through 43
BFrequencies shared with various unlicensed wireless data services
CHF frequencies where digital communications are permitted
DThe 60 meter band channel centered on 5373 kHz

11. - E2D01

Which of the following digital modes is designed for meteor scatter communications?

SelectAnswer
AMSK144
BHellschreiber
CWSPR
DAPRS

12. - E2E03

How is the timing of FT4 contacts organized?

SelectAnswer
AStations take turns on alternate days
BAlternating transmissions at 7.5 second intervals
CIt depends on the lunar phase
DBy exchanging ACK/NAK packets

13. - E3A03

When scheduling EME contacts, which of these conditions will generally result in the least path loss?

SelectAnswer
AWhen the moon is at apogee
BWhen the MUF is above 30 MHz
CWhen the moon is full
DWhen the moon is at perigee

14. - E3B03

What is the best time of day for transequatorial propagation?

SelectAnswer
ALate at night
BMorning
CNoon
DAfternoon or early evening

15. - E3C03

Which of the following signal paths is most likely to experience high levels of absorption when the A index or K index is elevated?

SelectAnswer
APolar
BNVIS
CTransequatorial
DSporadic E

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 analyzer near the antenna base
CLoosely couple the antenna and a dummy load to the analyzer
DConnect the analyzer via a high-impedance transformer to the antenna

17. - E4B07

What do the subscripts of S parameters represent?

SelectAnswer
AFrequency order of the measurements
BThe port or ports at which measurements are made
CRelative quality of the data
DThe relative time between measurements

18. - E4C11

Why can an attenuator be used to reduce receiver overload on the lower frequency HF bands with little or no impact on signal-to-noise ratio?

SelectAnswer
AThe attenuator has a low-pass filter to increase the strength of lower frequency signals
BAtmospheric noise is generally greater than internally generated noise even after attenuation
CSignals are attenuated separately from the noise
DThe attenuator has a noise filter to suppress interference

19. - E4D01

What is meant by the blocking dynamic range of a receiver?

SelectAnswer
AThe minimum difference in dB between two signals which produce third-order intermodulation products greater than the noise floor
BThe minimum difference in dB between the levels of two FM signals that will cause one signal to block the other
CThe difference in dB between the noise floor and the third-order intercept point
DThe difference in dB between the noise floor and the level of an incoming signal that will cause 1 dB of gain compression

20. - E4E08

What current flows equally on all conductors of an unshielded multi-conductor cable?

SelectAnswer
AReactive current only
BReturn current
CDifferential-mode current
DCommon-mode current

21. - E5A02

What is resonance in an LC or RLC circuit?

SelectAnswer
AThe lowest frequency that will pass current
BThe frequency at which the reactive impedance equals the resistive impedance
CThe frequency at which the capacitive reactance equals the inductive reactance
DThe highest frequency that will pass current

22. - E5B09

What is the relationship between the AC current through a capacitor and the voltage across a capacitor?

SelectAnswer
AVoltage and current are in phase
BVoltage and current are 180 degrees out of phase
CVoltage leads current by 90 degrees
DCurrent leads voltage by 90 degrees

23. - E5C08

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

SelectAnswer
AMaidenhead grid
BPolar coordinates
CFaraday grid
DElliptical coordinates

24. - E5D14

What is reactive power?

SelectAnswer
AWattless, nonproductive power
BPower consumed in wire resistance in an inductor
CPower lost because of capacitor leakage
DPower consumed in circuit Q

25. - E6A12

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

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

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. - E6C10

In Figure E6-3, what is the schematic symbol for a NOR gate?

SelectAnswer
A4
B1
C3
D2

28. - E6D13

What is the primary cause of inductor self-resonance?

SelectAnswer
AThe skin effect
BInter-turn capacitance
CInductive kickback
DNon-linear core hysteresis

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
BMMICs require no operating bias
CDirectly to the bias voltage (VCC IN) lead
DThrough a resistor and/or RF choke connected to the amplifier output lead

30. - E6F07

What is a solid-state relay?

SelectAnswer
AA mechanical relay that latches in the on or off state each time it is pulsed
BA device that uses semiconductors to implement the functions of an electromechanical relay
CA semiconductor passive delay line
DA relay using transistors to drive the relay coil

31. - E7A11

What type of logic defines "1" as a high voltage?

SelectAnswer
ANegative logic
BPositive Logic
CAssertive Logic
DReverse Logic

32. - E7B04

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

SelectAnswer
AApproximately halfway between saturation and cutoff
BWhere the load line intersects the voltage axis
CAt a point where the bias resistor equals the load resistor
DAt a point where the load line intersects the zero bias current curve

33. - E7C07

Which describes a Pi-L-network used for matching a vacuum tube final amplifier to a 50-ohm unbalanced output?

SelectAnswer
AA network with only three discrete parts
BA Phase Inverter Load network
CA Pi-network with an additional series inductor on the output
DA matching network in which all components are isolated from ground

34. - E7D08

What type of circuit is shown in Figure E7-2?

SelectAnswer
ASwitching voltage regulator
BMonostable multivibrator
CLinear voltage regulator
DGrounded emitter amplifier

35. - E7E04

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

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

36. - E7F08

What is the function of decimation?

SelectAnswer
AAttenuating the signal
BConverting data to binary code decimal form
CRemoving unnecessary significant digits
DReducing the effective sample rate by removing samples

37. - E7G09

What will be the output voltage of the circuit shown in Figure E7-3 if R1 is 1000 ohms, RF is 10,000 ohms, and 0.23 volts DC is applied to the input?

SelectAnswer
A0.23 volts
B-2.3 volts
C-0.23 volts
D2.3 volts

38. - E7H02

What is a microphonic?

SelectAnswer
AAn IC used for amplifying microphone signals
BChanges in oscillator frequency due to mechanical vibration
CExcess loading of the microphone by an oscillator
DDistortion caused by RF pickup on the microphone cable

39. - E8A11

Which of the following is a measure of the quality of an analog-to-digital converter?

SelectAnswer
APeak envelope power
BReciprocal mixing
CPower factor
DTotal harmonic distortion

40. - E8B03

What is the modulation index of an FM-phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency when the modulating frequency is 1000 Hz?

SelectAnswer
A1000
B3
C0.3
D3000

41. - E8C01

How is Forward Error Correction implemented?

SelectAnswer
ABy varying the frequency shift of the transmitted signal according to a predefined algorithm
BBy transmitting extra data that may be used to detect and correct transmission errors
CBy the receiving station repeating each block of three data characters
DBy transmitting a special algorithm to the receiving station along with the data characters

42. - E8D07

What is a common cause of overmodulation of AFSK signals?

SelectAnswer
AExcessive transmit audio levels
BExcessive numbers of retries
CGround loops
DBit errors in the modem

43. - E9A05

What is included in the total resistance of an antenna system?

SelectAnswer
ARadiation resistance plus transmission resistance
BRadiation resistance plus space impedance
CTransmission-line resistance plus radiation resistance
DRadiation resistance plus loss resistance

44. - E9B05

What type of antenna pattern is shown in Figure E9-2?

SelectAnswer
AAzimuth
BRadiation resistance
CElevation
DPolarization

45. - E9C02

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/4 wavelength apart and fed 90 degrees out of phase?

SelectAnswer
AA figure-8 end-fire along the axis of the array
BA figure-8 broadside to the axis of the array
COmni-directional
DCardioid

46. - E9D01

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

SelectAnswer
A3 dB
B4 dB
C6 dB
D2 dB

47. - E9E01

What system matches a higher-impedance transmission line to a lower-impedance antenna by connecting the line to the driven element in two places spaced a fraction of a wavelength each side of element center?

SelectAnswer
AThe omega matching system
BThe delta matching system
CThe gamma matching system
DThe stub matching system

48. - E9F09

What is the approximate physical length of a foam polyethylene dielectric coaxial transmission line that is electrically 1/4 wavelength long at 7.2 MHz?

SelectAnswer
A5.2 meters
B8.3 meters
C6.9 meters
D10.4 meters

49. - E9G08

What is the process of normalization with regard to a Smith chart?

SelectAnswer
AReassigning prime center with regard to the reactance axis
BReassigning resistance values with regard to the reactance axis
CReassigning reactance values with regard to the resistance axis
DReassigning impedance values with regard to the prime center

50. - E9H03

What is Receiving Directivity Factor (RDF)?

SelectAnswer
AForward gain compared to the gain in the reverse direction
BForward gain compared to average gain over the entire hemisphere
CRelative directivity compared to a dipole
DRelative directivity compared to isotropic

Figure E6-3

Figure E7-2

Figure E7-3

Figure E9-2