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

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1. - E0A11

Which of the following injuries can result from using high-power UHF or microwave transmitters?

Select	Answer
A	Hearing loss caused by high voltage corona discharge
B	Localized heating of the body from RF exposure in excess of the MPE limits
C	Ingestion of ozone gas from the cooling system
D	Blood clotting from the intense magnetic field

2. - E1A09

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

Select	Answer
A	Notify the originating station that the communication does not comply with FCC rules
B	Discontinue forwarding the communication as soon as you become aware of it
C	Notify the nearest FCC Field Engineers office
D	All these choices are correct

3. - E1B07

To what type of regulations does PRB-1 apply?

Select	Answer
A	Homeowners associations
B	State and local zoning
C	FAA tower height limits
D	Use of wireless devices in vehicles

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?

Select	Answer
A	At least 43 dB below
B	At least 53 dB below
C	At least 63 dB below
D	At least 73 dB below

5. - E1D09

Which UHF amateur bands have frequencies authorized for space stations?

Select	Answer
A	70 cm and 33 cm
B	70 cm and 13 cm
C	33 cm and 13 cm
D	70 cm only

6. - E1E08

To which of the following examinees may a VE not administer an examination?

Select	Answer
A	Employees of the VE
B	Friends of the VE
C	Relatives of the VE as listed in the FCC rules
D	All these choices are correct

7. - E1F04

Which of the following geographic descriptions approximately describes "Line A"?

Select	Answer
A	A line roughly parallel to and west of the U.S. Atlantic coastline
B	A line roughly parallel to and north of the border between the U.S. and Mexico
C	A line roughly parallel to and south of the border between the U.S. and Canada
D	A line roughly parallel to and east of the U.S. Pacific coastline

8. - E2A06

What are Keplerian elements?

Select	Answer
A	Encrypting codes used for spread spectrum modulation
B	Parameters that define the orbit of a satellite
C	High-emission heater filaments used in magnetron tubes
D	Phase reversing elements in a Yagi antenna

9. - E2B12

What signals SSTV receiving software to begin a new picture line?

Select	Answer
A	A two-tone signal
B	Specific tone frequencies
C	Elapsed time
D	Specific tone amplitudes

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.?

Select	Answer
A	No additional indicator is required
B	/R# where # is the district of the remote station
C	/ followed by the ARRL Section of the remote station
D	/ followed by the USPS two-letter abbreviation for the state in which the remote station is located

11. - E2D06

Which of the following describes a method of establishing EME contacts?

Select	Answer
A	Judging optimum transmission times by monitoring beacons reflected from the moon
B	High-speed CW identification to avoid fading
C	Storing and forwarding digital messages
D	Time synchronous transmissions alternately from each station

12. - E2E09

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

Select	Answer
A	PACTOR
B	PSK31
C	MT63
D	RTTY

13. - E3A14

What is meant by circularly polarized electromagnetic waves?

Select	Answer
A	Waves with a rotating electric field
B	Waves produced by a loop antenna
C	Waves that circle the Earth
D	Waves with an electric field bent into a circular shape

14. - E3B03

What is the best time of day for transequatorial propagation?

Select	Answer
A	Morning
B	Noon
C	Late at night
D	Afternoon or early evening

15. - E3C05

What orientation of Bz (B sub z) increases the likelihood that incoming particles from the sun will cause disturbed conditions?

Select	Answer
A	Southward
B	Westward
C	Eastward
D	Northward

16. - E4A02

Which of the following parameters does a spectrum analyzer display on the vertical and horizontal axes?

Select	Answer
A	RF amplitude and time
B	RF amplitude and frequency
C	SWR and frequency
D	SWR and time

17. - E4B08

Which of the following can be used to measure the Q of a series-tuned circuit?

Select	Answer
A	The resonant frequency of the circuit
B	The frequency shift
C	The bandwidth of the circuit's frequency response
D	The inductance to capacitance ratio

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?

Select	Answer
A	The attenuator has a noise filter to suppress interference
B	Atmospheric noise is generally greater than internally generated noise even after attenuation
C	Signals are attenuated separately from the noise
D	The attenuator has a low-pass filter to increase the strength of lower frequency signals

19. - E4D05

What transmitter frequencies would cause an intermodulation-product signal in a receiver tuned to 146.70 MHz when a nearby station transmits on 146.52 MHz?

Select	Answer
A	173.35 MHz and 139.40 MHz
B	146.88 MHz and 146.34 MHz
C	146.34 MHz and 146.61 MHz
D	146.10 MHz and 147.30 MHz

20. - E4E06

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

Select	Answer
A	A whining type noise that continually pulses off and on
B	A loud AC hum in the audio output of your station receiver
C	The appearance of unstable modulated or unmodulated signals at specific frequencies
D	A clicking noise at intervals of a few seconds

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?

Select	Answer
A	44.72 MHz
B	22.36 MHz
C	1.78 MHz
D	3.56 MHz

22. - E5B07

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 500 ohms, R is 1 kilohm, and XL is 250 ohms?

Select	Answer
A	68.2 degrees with the voltage leading the current
B	14.0 degrees with the voltage lagging the current
C	68.2 degrees with the voltage lagging the current
D	14.0 degrees with the voltage leading the current

23. - E5C12

Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and a 19-picofarad capacitor at 21.200 MHz?

Select	Answer
A	Point 1
B	Point 8
C	Point 3
D	Point 7

24. - E5D01

What is the result of skin effect?

Select	Answer
A	Thermal effects on the surface of the conductor increase the impedance
B	As frequency decreases, RF current flows in a thinner layer of the conductor, closer to the surface
C	As frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface
D	Thermal effects on the surface of the conductor decrease the impedance

25. - E6A04

What is the name given to an impurity atom that adds holes to a semiconductor crystal structure?

Select	Answer
A	Donor impurity
B	N-type impurity
C	Acceptor impurity
D	Insulator impurity

26. - E6B10

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

Select	Answer
A	1
B	5
C	7
D	6

27. - E6C08

In Figure E6-3, what is the schematic symbol for a NAND gate?

Select	Answer
A	3
B	1
C	4
D	2

28. - E6D12

What is inductor saturation?

Select	Answer
A	The inductor windings are over-coupled
B	The ability of the inductor's core to store magnetic energy has been exceeded
C	The inductor's voltage rating is exceeded causing a flashover
D	Adjacent inductors become over-coupled

29. - E6E08

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

Select	Answer
A	Through a capacitor and RF choke connected to the amplifier input lead
B	Directly to the bias voltage (VCC IN) lead
C	MMICs require no operating bias
D	Through a resistor and/or RF choke connected to the amplifier output lead

30. - E6F04

What is the photovoltaic effect?

Select	Answer
A	The conversion of electrical energy to mechanical energy
B	The tendency of a battery to discharge when exposed to light
C	The conversion of voltage to current when exposed to light
D	The conversion of light to electrical energy

31. - E7A10

What is a truth table?

Select	Answer
A	A table of logic symbols that indicate the high logic states of an op-amp
B	A list of inputs and corresponding outputs for a digital device
C	A diagram showing logic states when the digital device output is true
D	A table of logic symbols that indicate the logic states of an op-amp

32. - E7B06

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

Select	Answer
A	Class C
B	Push-pull
C	Push-push
D	Class AB

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?

Select	Answer
A	Greater harmonic suppression
B	Does not require a capacitor
C	Greater transformation range
D	Higher efficiency

34. - E7D02

What is a characteristic of a switching electronic voltage regulator?

Select	Answer
A	The controlled device's duty cycle is changed to produce a constant average output voltage
B	It is generally less efficient than a linear regulator
C	The resistance of a control element is varied in direct proportion to the line voltage or load current
D	It gives a ramp voltage at its output

35. - E7E10

How does a diode envelope detector function?

Select	Answer
A	By mixing signals with noise in the transition region of the diode
B	By breakdown of the Zener voltage
C	By sensing the change of reactance in the diode with respect to frequency
D	By rectification and filtering of RF signals

36. - E7F01

What is meant by direct digital conversion as applied to software defined radios?

Select	Answer
A	Incoming RF is converted to a control voltage for a voltage controlled oscillator
B	A switching mixer is used to generate I and Q signals directly from the RF input
C	Incoming RF is digitized by an analog-to-digital converter without being mixed with a local oscillator signal
D	Software is converted from source code to object code during operation of the receiver

37. - E7G01

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

Select	Answer
A	Very low
B	1000 ohms
C	100 ohms
D	Very high

38. - E7H02

What is a microphonic?

Select	Answer
A	Distortion caused by RF pickup on the microphone cable
B	An IC used for amplifying microphone signals
C	Changes in oscillator frequency due to mechanical vibration
D	Excess loading of the microphone by an oscillator

39. - E8A02

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

Select	Answer
A	Successive approximation
B	Phase reversal
C	Level shifting
D	Harmonic regeneration

40. - E8B11

What is digital time division multiplexing?

Select	Answer
A	Two or more data streams share the same channel by transmitting time of transmission as the sub-carrier
B	Two or more signals are quadrature modulated to increase bandwidth efficiency
C	Two or more data streams are assigned to discrete sub-carriers on an FM transmitter
D	Two or more signals are arranged to share discrete time slots of a data transmission

41. - E8C12

What factors affect the bandwidth of a transmitted CW signal?

Select	Answer
A	Keying speed and shape factor (rise and fall time)
B	IF bandwidth and Q
C	Modulation index and output power
D	All these choices are correct

42. - E8D02

What spread spectrum communications technique uses a high-speed binary bit stream to shift the phase of an RF carrier?

Select	Answer
A	Phase compandored spread spectrum
B	Binary phase-shift keying
C	Direct sequence
D	Frequency hopping

43. - E9A05

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

Select	Answer
A	Transmission-line resistance plus radiation resistance
B	Radiation resistance plus loss resistance
C	Radiation resistance plus space impedance
D	Radiation resistance plus transmission resistance

44. - E9B06

What is the elevation angle of peak response in the antenna radiation pattern shown in Figure E9-2?

Select	Answer
A	45 degrees
B	7.5 degrees
C	75 degrees
D	25 degrees

45. - E9C06

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

Select	Answer
A	It changes the radiation pattern from horizontal to vertical polarization
B	It changes the radiation pattern from bidirectional to unidirectional
C	It decreases the ground loss
D	It reflects the standing waves on the antenna elements back to the transmitter

46. - E9D11

Which of the following conductors would be best for minimizing losses in a station's RF ground system?

Select	Answer
A	Solid wire
B	Wide flat copper strap
C	Resistive wire, such as spark plug wire
D	Stranded wire

47. - E9E07

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

Select	Answer
A	Dielectric constant
B	Reflection coefficient
C	Characteristic impedance
D	Velocity factor

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?

Select	Answer
A	5.2 meters
B	8.3 meters
C	10.4 meters
D	6.9 meters

49. - E9G04

What are the two families of circles and arcs that make up a Smith chart?

Select	Answer
A	Resistance and reactance
B	Voltage and impedance
C	Resistance and voltage
D	Reactance and voltage

50. - E9H09

What is a Pennant antenna?

Select	Answer
A	A small, vertically oriented receiving antenna consisting of a triangular loop terminated in approximately 900 ohms
B	A form of rhombic antenna terminated in a variable capacitor to provide frequency diversity
C	A four-element, high-gain vertical array invented by George Pennant
D	A stealth antenna built to look like a flagpole

Figure E5-1

Figure E6-2

Figure E6-3

Figure E9-2