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	Blood clotting from the intense magnetic field
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	Hearing loss caused by high voltage corona discharge

2. - E1A13

Who must be in physical control of the station apparatus of an amateur station aboard any vessel or craft that is documented or registered in the United States?

Select	Answer
A	Only a person with an FCC Marine Radio license grant
B	Any person holding an FCC issued amateur license or who is authorized for alien reciprocal operation
C	Only a person named in an amateur station license grant
D	Any person named in an amateur station license grant or a person holding an unrestricted Radiotelephone Operator Permit

3. - E1B06

Which of the following additional rules apply if you are installing an amateur station antenna at a site at or near a public use airport?

Select	Answer
A	You must obtain a construction permit from the airport zoning authority
B	You must file an Environmental Impact Statement with the EPA before construction begins
C	You may have to notify the Federal Aviation Administration and register it with the FCC as required by Part 17 of the FCC rules
D	You must submit engineering drawings to the FAA

4. - E1C14

How long must an operator wait after filing a notification with the Utilities Technology Council (UTC) before operating on the 2200 meter or 630 meter band?

Select	Answer
A	Operators may operate after 30 days, providing they have not been told that their station is within 1 km of PLC systems using those frequencies
B	Operations may commence immediately, and may continue unless interference is reported by the UTC
C	Operators must not operate until approval is received
D	Operators may not operate until a test signal has been transmitted in coordination with the local power company

5. - E1D06

What is the maximum permitted transmitter output power when operating a model craft by telecommand?

Select	Answer
A	2 watts
B	100 watts
C	5 watts
D	1 watt

6. - E1E07

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

Select	Answer
A	Immediately terminate the candidate's examination
B	Warn the candidate that continued failure to comply will result in termination of the examination
C	Immediately terminate everyone's examination and close the session
D	Allow the candidate to complete the examination, but invalidate the results

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?

Select	Answer
A	53 MHz - 54 MHz
B	222 MHz - 223 MHz
C	420 MHz - 430 MHz
D	440 MHz - 450 MHz

8. - E2A03

How is the signal inverted by an inverting linear transponder?

Select	Answer
A	The signal is reduced to I and Q components and the Q component is filtered out
B	The signal is passed through a non-linear filter
C	The signal is passed through a mixer and the difference rather than the sum is transmitted
D	The signal is detected and remodulated on the reverse sideband

9. - E2B02

How many horizontal lines make up a fast-scan (NTSC) television frame?

Select	Answer
A	30
B	525
C	1080
D	60

10. - E2C11

How should you generally identify your station when attempting to contact a DX station during a contest or in a pileup?

Select	Answer
A	Send your full call sign and grid square
B	Send your full call sign once or twice
C	Send only the last two letters of your call sign until you make contact
D	Send the call sign of the DX station three times, the words this is,then your call sign three times

11. - E2D09

What type of modulation is used for JT65 contacts?

Select	Answer
A	Multi-tone AFSK
B	PSK
C	RTTY
D	IEEE 802.11

12. - E2E05

Which of these digital modes does not support keyboard-to-keyboard operation?

Select	Answer
A	PSK31
B	MFSK
C	PACTOR
D	RTTY

13. - E3A11

What is a typical range for tropospheric propagation of microwave signals?

Select	Answer
A	1200 miles
B	2500 miles
C	100 miles to 300 miles
D	10 miles to 50 miles

14. - E3B03

What is the best time of day for transequatorial propagation?

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

15. - E3C12

How does the maximum range of ground-wave propagation change when the signal frequency is increased?

Select	Answer
A	It stays the same
B	It decreases
C	It increases
D	It peaks at roughly 14 MHz

16. - E4A10

Which of the following displays multiple digital signal states simultaneously?

Select	Answer
A	Modulation monitor
B	Logic analyzer
C	Bit error rate tester
D	Network analyzer

17. - E4B03

Which S parameter is equivalent to forward gain?

Select	Answer
A	S21
B	S11
C	S22
D	S12

18. - E4C03

What is the term for the suppression in an FM receiver of one signal by another stronger signal on the same frequency?

Select	Answer
A	Desensitization
B	Frequency discrimination
C	Cross-modulation interference
D	Capture effect

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

20. - E4E04

How can conducted and radiated noise caused by an automobile alternator be suppressed?

Select	Answer
A	By installing a high-pass filter in series with the radio's power lead and a low-pass filter in parallel with the field lead
B	By installing a noise suppression resistor and a blocking capacitor in both leads
C	By connecting the radio's power leads directly to the battery and by installing coaxial capacitors in line with the alternator leads
D	By installing filter capacitors in series with the DC power lead and a blocking capacitor in the field lead

21. - E5A12

What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 3.7 MHz and a Q of 118?

Select	Answer
A	15.7 kHz
B	218.3 kHz
C	31.4 kHz
D	436.6 kHz

22. - E5B03

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

Select	Answer
A	Take the square root of the magnitude and add 180 degrees to the angle
B	Take the reciprocal of the angle and change the sign of the magnitude
C	Square the magnitude and subtract 90 degrees from the angle
D	Take the reciprocal of the magnitude and change the sign of the angle

23. - E5C01

Which of the following represents capacitive reactance in rectangular notation?

Select	Answer
A	Delta
B	+jX
C	Omega
D	-jX

24. - E5D07

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

Select	Answer
A	1.42 mW
B	252 W
C	355 W
D	704 W

25. - E6A08

What term indicates the frequency at which the grounded-base current gain of a transistor has decreased to 0.7 of the gain obtainable at 1 kHz?

Select	Answer
A	Alpha cutoff frequency
B	Alpha rejection frequency
C	Corner frequency
D	Beta cutoff frequency

26. - E6B05

What characteristic of a PIN diode makes it useful as an RF switch?

Select	Answer
A	Ability to dissipate large amounts of power
B	Reverse bias controls its forward voltage drop
C	Extremely high reverse breakdown voltage
D	Low junction capacitance

27. - E6C10

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

Select	Answer
A	2
B	1
C	4
D	3

28. - E6D06

What core material property determines the inductance of an inductor?

Select	Answer
A	Resistance
B	Reactivity
C	Permeability
D	Thermal impedance

29. - E6E05

Which of the following noise figure values is typical of a low-noise UHF preamplifier?

Select	Answer
A	2 dB
B	-10 dB
C	44 dBm
D	-20 dBm

30. - E6F11

What is the approximate open-circuit voltage produced by a fully illuminated silicon photovoltaic cell?

Select	Answer
A	0.1 V
B	12 V
C	1.5 V
D	0.5 V

31. - E7A02

What is the function of a decade counter?

Select	Answer
A	It produces 10 output pulses for every input pulse
B	It produces one output pulse for every 10 input pulses
C	It decodes a binary number for display on a seven-segment LED display
D	It decodes a decimal number for display on a seven-segment LED display

32. - E7B06

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

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

33. - E7C01

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

Select	Answer
A	Two capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground
B	A 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
C	Two inductors are in series between the input and output, and a capacitor is connected between the two inductors and ground
D	An 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

34. - E7D04

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

Select	Answer
A	A series regulator
B	A shunt regulator
C	A series current source
D	A shunt current source

35. - E7E10

How does a diode envelope detector function?

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

36. - E7F14

Which of the following would allow a digital signal processing filter to create a sharper filter response?

Select	Answer
A	Complex phasor representations
B	Higher data rate
C	More taps
D	Double-precision math routines

37. - E7G08

How does the gain of an ideal operational amplifier vary with frequency?

Select	Answer
A	It decreases linearly with increasing frequency
B	It increases linearly with increasing frequency
C	It decreases logarithmically with increasing frequency
D	It does not vary with frequency

38. - E7H03

How is positive feedback supplied in a Hartley oscillator?

Select	Answer
A	Through a tapped coil
B	Through link coupling
C	Through a capacitive divider
D	Through a neutralizing capacitor

39. - E8A03

What type of wave does a Fourier analysis show to be made up of sine waves of a given fundamental frequency plus all its harmonics?

Select	Answer
A	A square wave
B	A sawtooth wave
C	A sine wave
D	A cosine wave

40. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

Select	Answer
A	A digital modulation technique using subcarriers at frequencies chosen to avoid intersymbol interference
B	A bandwidth compression technique using Fourier transforms
C	A frequency modulation technique that uses non-harmonically related frequencies
D	A digital mode for narrow-band, slow-speed transmissions

41. - E8C11

What is the relationship between symbol rate and baud?

Select	Answer
A	They are the same
B	Baud is twice the symbol rate
C	Symbol rate is only used for packet-based modes
D	Baud is only used for RTTY

42. - E8D09

What is considered an acceptable maximum IMD level for an idling PSK signal?

Select	Answer
A	+10 dB
B	-20 dB
C	+15 dB
D	-30 dB

43. - E9A01

What is an isotropic antenna?

Select	Answer
A	A horizontally polarized antenna used to compare Yagi antennas
B	A spacecraft antenna used to direct signals toward Earth
C	A theoretical, omnidirectional antenna used as a reference for antenna gain
D	A grounded antenna used to measure Earth conductivity

44. - E9B04

What is the front-to-back ratio of the radiation pattern shown in Figure E92?

Select	Answer
A	15 dB
B	38 dB
C	3 dB
D	28 dB

45. - E9C04

What happens to the radiation pattern of an unterminated long wire antenna as the wire length is increased?

Select	Answer
A	The vertical angle increases
B	The lobes become more perpendicular to the wire
C	The lobes align more in the direction of the wire
D	The front-to-back ratio decreases

46. - E9D07

What is an advantage of using top loading in a shortened HF vertical antenna?

Select	Answer
A	Greater structural strength
B	Higher losses
C	Lower Q
D	Improved radiation efficiency

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?

Select	Answer
A	The omega matching system
B	The gamma matching system
C	The delta matching system
D	The stub matching system

48. - E9F11

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

Select	Answer
A	The same as the characteristic impedance of the line
B	An inductive reactance
C	A capacitive reactance
D	Infinite

49. - E9G10

What do the arcs on a Smith chart represent?

Select	Answer
A	Frequency
B	Points with constant resistance
C	SWR
D	Points with constant reactance

50. - E9H02

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

Select	Answer
A	Low loss coax transmission line is essential for good performance
B	All these choices are correct
C	They must be erected at least 1/2 wavelength above the ground to attain good directivity
D	Atmospheric noise is so high that gain over a dipole is not important

Figure E6-3