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

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1. - E0A02

When evaluating RF exposure levels from your station at a neighbor's home, what must you do?

Select	Answer
A	Ensure signals from your station are less than the uncontrolled Maximum Permitted Emission (MPE) limits
B	Ensure signals from your station are less than the controlled Maximum Permitted Emission (MPE) limits
C	Ensure signals from your station are less than the uncontrolled Maximum Permitted Exposure (MPE) limits
D	Ensure signals from your station are less than the controlled Maximum Permitted Exposure (MPE) limits

2. - E1A08

If a station in a message forwarding system inadvertently forwards a message that is in violation of FCC rules, who is primarily accountable for the rules violation?

Select	Answer
A	The control operator of the packet bulletin board station
B	The control operators of all the stations in the system not authenticating the source from which they accept communications
C	The control operators of all the stations in the system
D	The control operator of the originating station

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 file an Environmental Impact Statement with the EPA before construction begins
B	You must obtain a construction permit from the airport zoning authority
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. - E1C09

What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?

Select	Answer
A	1.0
B	3.0
C	2.0
D	0.5

5. - E1D08

Which VHF amateur bands have frequencies authorized for space stations?

Select	Answer
A	6 meters, 2 meters, and 1.25 meters
B	2 meters
C	6 meters and 2 meters
D	2 meters and 1.25 meters

6. - E1E10

What must the administering VEs do after the administration of a successful examination for an amateur operator license?

Select	Answer
A	They must collect and send the documents to the NCVEC for grading
B	They must collect and submit the documents to the coordinating VEC for grading
C	They must collect and send the documents to the FCC according to instructions
D	They must submit the application document to the coordinating VEC according to the coordinating VEC instructions

7. - E1F11

Which of the following best describes one of the standards that must be met by an external RF power amplifier if it is to qualify for a grant of FCC certification?

Select	Answer
A	It must exhibit a gain of 0 dB or less over its full output range
B	It must satisfy the FCC's spurious emission standards when operated at the lesser of 1500 watts or its full output power
C	It must produce full legal output when driven by not more than 5 watts of mean RF input power
D	It must be capable of external RF switching between its input and output networks

8. - E2A06

What are Keplerian elements?

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

9. - E2B03

How is an interlaced scanning pattern generated in a fast-scan (NTSC) television system?

Select	Answer
A	By scanning lines from left to right in one field and right to left in the next
B	By scanning each field from bottom to top
C	By scanning two fields simultaneously
D	By scanning odd numbered lines in one field and even numbered lines in the next

10. - E2C03

From which of the following bands is amateur radio contesting generally excluded?

Select	Answer
A	2 meters
B	33 centimeters
C	30 meters
D	6 meters

11. - E2D05

What is one advantage of the JT65 mode?

Select	Answer
A	Permits fast-scan TV transmissions over narrow bandwidth
B	Uses only a 65 Hz bandwidth
C	Easily copied by ear if necessary
D	The ability to decode signals which have a very low signal-to-noise ratio

12. - E2E05

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

Select	Answer
A	RTTY
B	MFSK
C	PSK31
D	PACTOR

13. - E3A01

What is the approximate maximum separation measured along the surface of the Earth between two stations communicating by EME?

Select	Answer
A	2000 miles, if the moon is at apogee
B	12,000 miles, if the moon is visible by both stations
C	500 miles, if the moon is at perigee
D	5000 miles, if the moon is at perigee

14. - E3B04

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

Select	Answer
A	Independent waves created in the ionosphere that are elliptically polarized
B	Refracted rays and reflected waves
C	Extraordinary waves describe rare long-skip propagation compared to ordinary waves, which travel shorter distances
D	Long-path and short-path waves

15. - E3C11

What does VOACAP software model?

Select	Answer
A	AC current and impedance
B	HF propagation
C	VHF radio propagation
D	AC voltage and impedance

16. - E4A01

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

Select	Answer
A	Sampling rate of the analog-to-digital converter
B	Q of the circuit
C	All these choices are correct
D	Amount of memory

17. - E4B01

Which of the following factors most affects the accuracy of a frequency counter?

Select	Answer
A	Temperature coefficient of the logic
B	Time base accuracy
C	Input attenuator accuracy
D	Decade divider accuracy

18. - E4C01

What is an effect of excessive phase noise in a receiver's local oscillator?

Select	Answer
A	It decreases receiver third-order intercept point
B	It limits the receiver's ability to receive strong signals
C	It can affect the receiver's frequency calibration
D	It can combine with strong signals on nearby frequencies to generate interference

19. - E4D07

Which of the following reduces the likelihood of receiver desensitization?

Select	Answer
A	Raise the receiver IF frequency
B	Decrease the RF bandwidth of the receiver
C	Switch from fast AGC to slow AGC
D	Increase the receiver front end gain

20. - E4E01

What problem can occur when using an automatic notch filter (ANF) to remove interfering carriers while receiving CW signals?

Select	Answer
A	Any nearby signal passing through the DSP system will overwhelm the desired signal
B	Received CW signals will appear to be modulated at the DSP clock frequency
C	Removal of the CW signal as well as the interfering carrier
D	Ringing in the DSP filter will completely remove the spaces between the CW characters

21. - E5A15

Which of the following increases Q for inductors and capacitors?

Select	Answer
A	Lower losses
B	Lower reactance
C	Lower self-resonant frequency
D	Higher self-resonant frequency

22. - E5B01

What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the applied voltage or to discharge to 36.8% of its initial voltage?

Select	Answer
A	One time constant
B	A time factor of one
C	One exponential period
D	An exponential rate of one

23. - E5C10

Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 400-ohm resistor and a 38-picofarad capacitor at 14 MHz?

Select	Answer
A	Point 2
B	Point 6
C	Point 5
D	Point 4

24. - E5D09

What happens to reactive power in an AC circuit that has both ideal inductors and ideal capacitors?

Select	Answer
A	It is dissipated as kinetic energy in the circuit
B	It is dissipated in the formation of inductive and capacitive fields
C	It is repeatedly exchanged between the associated magnetic and electric fields, but is not dissipated
D	It is dissipated as heat in the circuit

25. - E6A06

What is the beta of a bipolar junction transistor?

Select	Answer
A	The switching speed
B	The change in collector current with respect to base current
C	The breakdown voltage of the base to collector junction
D	The frequency at which the current gain is reduced to 0.707

26. - E6B01

What is the most useful characteristic of a Zener diode?

Select	Answer
A	A constant current drop under conditions of varying voltage
B	A negative resistance region
C	An internal capacitance that varies with the applied voltage
D	A constant voltage drop under conditions of varying current

27. - E6C02

What happens when the level of a comparator's input signal crosses the threshold?

Select	Answer
A	The comparator enters latch-up
B	The comparator changes its output state
C	The feedback loop becomes unstable
D	The IC input can be damaged

28. - E6D02

What is the equivalent circuit of a quartz crystal?

Select	Answer
A	Motional inductance and loss resistance in series, paralleled with motional capacitance and a capacitor representing electrode and stray capacitance
B	Motional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in series
C	Motional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in parallel
D	Motional capacitance, motional inductance, and loss resistance in series, all in parallel with a shunt capacitor representing electrode and stray capacitance

29. - E6E11

What is a characteristic of DIP packaging used for integrated circuits?

Select	Answer
A	A total of two rows of connecting pins placed on opposite sides of the package (Dual In-line Package)
B	Low leakage doubly insulated package
C	Two chips in each package (Dual In Package)
D	Package mounts in a direct inverted position

30. - E6F03

What is the most common configuration of an optoisolator or optocoupler?

Select	Answer
A	An amplitude modulated helium-neon laser
B	A frequency modulated helium-neon laser
C	An LED and a phototransistor
D	A lens and a photomultiplier

31. - E7A02

What is the function of a decade counter?

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

32. - E7B14

Why are switching amplifiers more efficient than linear amplifiers?

Select	Answer
A	Linear amplifiers have high gain resulting in higher harmonic content
B	The power transistor is at saturation or cutoff most of the time
C	Switching amplifiers use push-pull circuits
D	Switching amplifiers operate at higher voltages

33. - E7C10

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

Select	Answer
A	An L-C filter
B	A crystal filter
C	A cavity filter
D	A DSP filter

34. - E7D12

What is the dropout voltage of an analog voltage regulator?

Select	Answer
A	Minimum input-to-output voltage required to maintain regulation
B	Minimum input voltage for rated power dissipation
C	Maximum that the output voltage may decrease at rated load
D	Maximum output voltage drops when the input voltage is varied over its specified range

35. - E7E01

Which of the following can be used to generate FM phone emissions?

Select	Answer
A	A reactance modulator on the oscillator
B	A reactance modulator on the final amplifier
C	A balanced modulator on the oscillator
D	A balanced modulator on the audio amplifier

36. - E7F13

What is the function of taps in a digital signal processing filter?

Select	Answer
A	Provide incremental signal delays for filter algorithms
B	Select the point at which baseband signals are generated
C	Provide access for debugging software
D	To reduce excess signal pressure levels

37. - E7G02

What is ringing in a filter?

Select	Answer
A	An echo caused by a long time delay
B	Partial cancellation of the signal over a range of frequencies
C	Undesired oscillations added to the desired signal
D	A reduction in high frequency response

38. - E7H11

What are the major spectral impurity components of direct digital synthesizers?

Select	Answer
A	Nyquist limit noise
B	Broadband noise
C	Spurious signals at discrete frequencies
D	Digital conversion noise

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

40. - E8B05

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus-or-minus 5 kHz when the maximum modulation frequency is 3 kHz?

Select	Answer
A	0.6
B	60
C	1.67
D	0.167

41. - E8C12

What factors affect the bandwidth of a transmitted CW signal?

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

42. - E8D09

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

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

43. - E9A05

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

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

44. - E9B04

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

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

45. - E9C08

What is a folded dipole antenna?

Select	Answer
A	A dipole configured to provide forward gain
B	A dipole one-quarter wavelength long
C	A type of ground-plane antenna
D	A half-wave dipole with an additional parallel wire connecting its two ends

46. - E9D08

What happens as the Q of an antenna increases?

Select	Answer
A	More common-mode current is present on the feed line
B	Gain is reduced
C	SWR bandwidth decreases
D	SWR bandwidth increases

47. - E9E02

What is the name of an antenna matching system that matches an unbalanced feed line to an antenna by feeding the driven element both at the center of the element and at a fraction of a wavelength to one side of center?

Select	Answer
A	The stub match
B	The delta match
C	The epsilon match
D	The gamma match

48. - E9F10

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

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

49. - E9G05

Which of the following is a common use for a Smith chart?

Select	Answer
A	Determine the impedance of a transmission line, given the physical dimensions
B	Determine the loss/100 feet of a transmission line, given the velocity factor and conductor materials
C	Determine the gain of an antenna given the physical and electrical parameters
D	Determine the length and position of an impedance matching stub

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	Atmospheric noise is so high that gain over a dipole is not important
C	They must be erected at least 1/2 wavelength above the ground to attain good directivity
D	All these choices are correct

Figure E5-1