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

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1. - E0A06

Why are there separate electric (E) and magnetic (H) field MPE limits?

Select	Answer
A	E field and H field radiation intensity peaks can occur at different locations
B	The body reacts to electromagnetic radiation from both the E and H fields
C	Ground reflections and scattering make the field strength vary with location
D	All these choices are correct

2. - E1A14

Except in some parts of Alaska, what is the maximum power permitted on the 630 meter band?

Select	Answer
A	1 watt EIRP
B	100 watts PEP
C	5 watts EIRP
D	50 watts PEP

3. - E1B07

To what type of regulations does PRB-1 apply?

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

4. - E1C01

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

Select	Answer
A	1.5 kHz
B	2.8 kHz
C	60 Hz
D	170 Hz

5. - E1D08

Which VHF amateur bands have frequencies authorized for space stations?

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

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

7. - E1F01

On what frequencies are spread spectrum transmissions permitted?

Select	Answer
A	Only on amateur frequencies above 50 MHz
B	Only on amateur frequencies above 420 MHz
C	Only on amateur frequencies above 222 MHz
D	Only on amateur frequencies above 144 MHz

8. - E2A07

Which of the following types of signals can be relayed through a linear transponder?

Select	Answer
A	SSB and SSTV
B	All these choices are correct
C	FM and CW
D	PSK and packet

9. - E2B10

What aspect of an analog slow-scan television signal encodes the brightness of the picture?

Select	Answer
A	Tone frequency
B	Sync amplitude
C	Tone amplitude
D	Sync frequency

10. - E2C08

Which of the following contacts may be confirmed through the U.S. QSL bureau system?

Select	Answer
A	Contacts between a U.S. station and a non-U.S. station
B	Contacts using tactical call signs
C	Repeater contacts between U.S. club members
D	Special event contacts between stations in the U.S.

11. - E2D02

Which of the following is a good technique for making meteor scatter contacts?

Select	Answer
A	Use of special digital modes
B	Short transmissions with rapidly repeated call signs and signal reports
C	15-second timed transmission sequences with stations alternating based on location
D	All these choices are correct

12. - E2E04

What is indicated when one of the ellipses in an FSK crossed-ellipse display suddenly disappears?

Select	Answer
A	The receiver has drifted 5 kHz from the desired receive frequency
B	Selective fading has occurred
C	One of the signal filters is saturated
D	The mark and space signal have been inverted

13. - E3A09

Which of the following frequency ranges is most suited for meteor scatter communications?

Select	Answer
A	28 MHz - 148 MHz
B	220 MHz - 450 MHz
C	1.8 MHz - 1.9 MHz
D	10 MHz - 14 MHz

14. - E3B02

What is the approximate maximum range for signals using transequatorial propagation?

Select	Answer
A	7500 miles
B	5000 miles
C	2500 miles
D	1000 miles

15. - E3C02

What is indicated by a rising A or K index?

Select	Answer
A	An increase in the critical frequency
B	Higher levels of solar UV radiation
C	Decreasing disruption of the geomagnetic field
D	Increasing disruption of the geomagnetic field

16. - E4A06

What is the effect of aliasing on a digital oscilloscope caused by setting the time base too slow?

Select	Answer
A	Excessive blanking occurs, which prevents display of the signal
B	Calibration of the vertical scale is no longer valid
C	A false, jittery low-frequency version of the signal is displayed
D	All signals will have a DC offset

17. - E4B04

Which S parameter represents input port return loss or reflection coefficient (equivalent to VSWR)?

Select	Answer
A	S11
B	S22
C	S12
D	S21

18. - E4C09

Which of the following choices is a good reason for selecting a high frequency for the design of the IF in a superheterodyne HF or VHF communications receiver?

Select	Answer
A	Improved receiver noise figure
B	Easier for front-end circuitry to eliminate image responses
C	Reduced drift
D	Fewer components in the receiver

19. - E4D08

What causes intermodulation in an electronic circuit?

Select	Answer
A	Too little gain
B	Lack of neutralization
C	Positive feedback
D	Nonlinear circuits or devices

20. - E4E08

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

Select	Answer
A	Return current
B	Differential-mode current
C	Reactive current only
D	Common-mode current

21. - E5A10

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

Select	Answer
A	Reactance of the inductance multiplied by the reactance of the capacitance
B	Resistance divided by the reactance of either the inductance or capacitance
C	Reactance of either the inductance or capacitance multiplied by the resistance
D	Reactance of either the inductance or capacitance divided by the resistance

22. - E5B02

What letter is commonly used to represent susceptance?

Select	Answer
A	B
B	G
C	Y
D	X

23. - E5C11

Which point in Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and an 18-microhenry inductor at 3.505 MHz?

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

24. - E5D14

What is reactive power?

Select	Answer
A	Power consumed in circuit Q
B	Wattless, nonproductive power
C	Power consumed in wire resistance in an inductor
D	Power lost because of capacitor leakage

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 rejection frequency
B	Corner frequency
C	Beta cutoff frequency
D	Alpha cutoff frequency

26. - E6B06

Which of the following is a common use of a Schottky diode?

Select	Answer
A	As a constant voltage reference in a power supply
B	As a rectifier in high current power supplies
C	As a VHF/UHF mixer or detector
D	As a variable capacitance in an automatic frequency control circuit

27. - E6C07

What best describes a pull-up or pull-down resistor?

Select	Answer
A	A resistor that ensures that an oscillator frequency does not drift
B	A resistor connected to the positive or negative supply line used to establish a voltage when an input or output is an open circuit
C	A resistor connected to an op-amp output that prevents signals from exceeding the power supply voltage
D	A resistor in a keying circuit used to reduce key clicks

28. - E6D12

What is inductor saturation?

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

29. - E6E02

Which of the following device packages is a through-hole type?

Select	Answer
A	DIP
B	PLCC
C	SOT
D	Ball grid array

30. - E6F07

What is a solid-state relay?

Select	Answer
A	A semiconductor passive delay line
B	A device that uses semiconductors to implement the functions of an electromechanical relay
C	A mechanical relay that latches in the on or off state each time it is pulsed
D	A relay using transistors to drive the relay coil

31. - E7A10

What is a truth table?

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

32. - E7B11

In Figure E7-1, what is the purpose of R3?

Select	Answer
A	Self bias
B	Output load resistor
C	Emitter bypass
D	Fixed bias

33. - E7C08

Which of the following factors has the greatest effect on the bandwidth and response shape of a crystal ladder filter?

Select	Answer
A	The gain of the RF stage preceding the filter
B	The relative frequencies of the individual crystals
C	The DC voltage applied to the quartz crystal
D	The amplitude of the signals passing through the filter

34. - E7D08

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

Select	Answer
A	Monostable multivibrator
B	Switching voltage regulator
C	Linear voltage regulator
D	Grounded emitter amplifier

35. - E7E02

What is the function of a reactance modulator?

Select	Answer
A	To produce PM or FM signals by using an electrically variable inductance or capacitance
B	To produce AM signals by using an electrically variable resistance
C	To produce AM signals by using an electrically variable inductance or capacitance
D	To produce PM signals by using an electrically variable resistance

36. - E7F12

Which of the following is an advantage of a Finite Impulse Response (FIR) filter vs an Infinite Impulse Response (IIR) digital filter?

Select	Answer
A	FIR filters are easier to implement for a given set of passband rolloff requirements
B	FIR filters can respond faster to impulses
C	FIR filters can delay all frequency components of the signal by the same amount
D	All these choices are correct

37. - E7G04

What is meant by the "op-amp input offset voltage"?

Select	Answer
A	The output voltage of the op-amp minus its input voltage
B	The difference between the output voltage of the op-amp and the input voltage required in the immediately following stage
C	The differential input voltage needed to bring the open loop output voltage to zero
D	The potential between the amplifier input terminals of the op-amp in an open loop condition

38. - E7H10

What information is contained in the lookup table of a direct digital synthesizer (DDS)?

Select	Answer
A	The phase relationship between a reference oscillator and the output waveform
B	The phase relationship between a voltage-controlled oscillator and the output waveform
C	Amplitude values that represent the desired waveform
D	Frequently used receiver and transmitter frequencies

39. - E8A08

Why would a direct or flash conversion analog-to-digital converter be useful for a software defined radio?

Select	Answer
A	Very high speed allows digitizing high frequencies
B	Immunity to out-of-sequence coding reduces spurious responses
C	Very low power consumption decreases frequency drift
D	All these choices are correct

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. - E8C08

How does ARQ accomplish error correction?

Select	Answer
A	If errors are detected, redundant data is substituted
B	If errors are detected, a retransmission is requested
C	Special binary codes provide automatic correction
D	Special polynomial codes provide automatic correction

42. - E8D03

How does the spread spectrum technique of frequency hopping work?

Select	Answer
A	If interference is detected by the receiver it will signal the transmitter to change frequencies
B	The frequency of the transmitted signal is changed very rapidly according to a pseudorandom sequence also used by the receiving station
C	A binary bit stream is used to shift the phase of an RF carrier very rapidly in a pseudorandom sequence
D	If interference is detected by the receiver it will signal the transmitter to wait until the frequency is clear

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	Radiation resistance plus space impedance
D	Transmission-line resistance plus radiation resistance

44. - E9B08

What is the far field of an antenna?

Select	Answer
A	The region where radiated power dissipates over a specified time period
B	The region where the shape of the antenna pattern is independent of distance
C	The region of the ionosphere where radiated power is not refracted
D	The region where radiated field strengths are constant

45. - E9C04

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

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

46. - E9D05

What usually occurs if a Yagi antenna is designed solely for maximum forward gain?

Select	Answer
A	The frequency response is widened over the whole frequency band
B	The front-to-back ratio decreases
C	The front-to-back ratio increases
D	The SWR is reduced

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 gamma match
C	The delta match
D	The epsilon match

48. - E9F03

Why is the physical length of a coaxial cable transmission line shorter than its electrical length?

Select	Answer
A	Electrical signals move more slowly in a coaxial cable than in air
B	The surge impedance is higher in a parallel feed line
C	The characteristic impedance is higher in a parallel feed line
D	Skin effect is less pronounced in the coaxial cable

49. - E9G06

On the Smith chart shown in Figure E9-3, what is the name for the large outer circle on which the reactance arcs terminate?

Select	Answer
A	Polar axis
B	Reactance axis
C	Impedance axis
D	Prime axis

50. - E9H09

What is a Pennant antenna?

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

Figure E5-1

Figure E7-1

Figure E7-2

Figure E9-3