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

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1. - E0A01

What is the primary function of an external earth connection or ground rod?

Select	Answer
A	Reduce RFI to telephones and home entertainment systems
B	Lightning protection
C	Reduce RF current flow between pieces of equipment
D	Reduce received noise

2. - E1A07

What is the maximum power permitted on the 2200 meter band?

Select	Answer
A	50 watts PEP
B	5 watts EIRP (Equivalent isotropic radiated power)
C	100 watts PEP
D	1 watt EIRP (Equivalent isotropic radiated power)

3. - E1B12

What must the control operator of a repeater operating in the 70 cm band do if a radiolocation system experiences interference from that repeater?

Select	Answer
A	Cease operation or make changes to the repeater to mitigate the interference
B	All these choices are correct
C	File an FAA NOTAM (Notice to Airmen) with the repeater system's ERP, call sign, and six-character grid locator
D	Reduce the repeater antenna HAAT (Height Above Average Terrain)

4. - E1C07

At what level below a signal's mean power level is its bandwidth determined according to FCC rules?

Select	Answer
A	23 dB
B	26 dB
C	3 dB
D	6 dB

5. - E1D12

Which of the following amateur stations may transmit one-way communications?

Select	Answer
A	A message forwarding station or automatically controlled digital station
B	All these choices are correct
C	A space station, beacon station, or telecommand station
D	A local repeater or linked repeater station

6. - E1E08

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

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

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

8. - E2A02

Which of the following occurs when a satellite is using an inverting linear transponder?

Select	Answer
A	Doppler shift is reduced because the uplink and downlink shifts are in opposite directions
B	Signal position in the band is reversed
C	Upper sideband on the uplink becomes lower sideband on the downlink, and vice versa
D	All these choices are correct

9. - E2B02

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

Select	Answer
A	1080
B	60
C	525
D	30

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

11. - E2D01

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

Select	Answer
A	Hellschreiber
B	APRS
C	WSPR
D	MSK144

12. - E2E05

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

Select	Answer
A	MFSK
B	PSK31
C	PACTOR
D	RTTY

13. - E3A12

What is the cause of auroral activity?

Select	Answer
A	Meteor showers concentrated in the extreme northern and southern latitudes
B	The interaction in the E layer of charged particles from the Sun with the Earth's magnetic field
C	The interaction in the F2 layer between the solar wind and the Van Allen belt
D	An extreme low-pressure area in the polar regions

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 increases
C	It decreases
D	It peaks at roughly 14 MHz

16. - E4A05

What is the purpose of the prescaler function on a frequency counter?

Select	Answer
A	It multiplies a higher frequency signal so a low-frequency counter can display the operating frequency
B	It divides a higher frequency signal so a low-frequency counter can display the input frequency
C	It prevents oscillation in a low-frequency counter circuit
D	It amplifies low-level signals for more accurate counting

17. - E4B01

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

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

18. - E4C01

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

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

19. - E4D02

Which of the following describes problems caused by poor dynamic range in a receiver?

Select	Answer
A	Oscillator instability and severe audio distortion of all but the strongest received signals
B	Spurious signals caused by cross-modulation and desensitization from strong adjacent signals
C	Cross-modulation of the desired signal and insufficient audio power to operate the speaker
D	Oscillator instability requiring frequent retuning and loss of ability to recover the opposite sideband

20. - E4E04

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

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

21. - E5A05

What is the result of increasing the Q of an impedance-matching circuit?

Select	Answer
A	Matching range is increased
B	It has no effect on impedance matching
C	Matching bandwidth is decreased
D	Matching bandwidth is increased

22. - E5B08

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 100 ohms, R is 100 ohms, and XL is 75 ohms?

Select	Answer
A	76 degrees with the voltage leading the current
B	76 degrees with the voltage lagging the current
C	14 degrees with the voltage lagging the current
D	14 degrees with the voltage leading the current

23. - E5C09

When using rectangular coordinates to graph the impedance of a circuit, what do the axes represent?

Select	Answer
A	The X axis represents the resistive component and the Y axis represents the reactive component
B	The X axis represents the reactive component and the Y axis represents the resistive component
C	The X axis represents the magnitude and the Y axis represents the phase angle
D	The X axis represents the phase angle and the Y axis represents the magnitude

24. - E5D12

How many watts are consumed in a circuit having a power factor of 0.2 if the input is 100 VAC at 4 amperes?

Select	Answer
A	2000 watts
B	80 watts
C	50 watts
D	400 watts

25. - E6A12

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

Select	Answer
A	To reduce the chance of static damage to the gate
B	To protect the substrate from excessive voltages
C	To keep the gate voltage within specifications and prevent the device from overheating
D	To provide a voltage reference for the correct amount of reverse-bias gate voltage

26. - E6B03

What type of bias is required for an LED to emit light?

Select	Answer
A	Reverse bias
B	Inductive bias
C	Zero bias
D	Forward bias

27. - E6C07

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

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

28. - E6D03

Which of the following is an aspect of the piezoelectric effect?

Select	Answer
A	Mechanical deformation of material by the application of a voltage
B	Mechanical deformation of material by the application of a magnetic field
C	Generation of electrical energy in the presence of light
D	Increased conductivity in the presence of light

29. - E6E01

Why is gallium arsenide (GaAs) useful for semiconductor devices operating at UHF and higher frequencies?

Select	Answer
A	Higher electron mobility
B	Higher noise figures
C	Lower junction voltage drop
D	Lower transconductance

30. - E6F09

What is the efficiency of a photovoltaic cell?

Select	Answer
A	The relative fraction of light that is converted to current
B	The output RF power divided by the input DC power
C	Cost per kilowatt-hour generated
D	The open-circuit voltage divided by the short-circuit current under full illumination

31. - E7A01

Which circuit is bistable?

Select	Answer
A	An AND gate
B	A bipolar amplifier
C	An OR gate
D	A flip-flop

32. - E7B06

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

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

33. - E7C06

What are the distinguishing features of an elliptical filter?

Select	Answer
A	Extremely flat response over its pass band with gradually rounded stop band corners
B	Gradual passband rolloff with extreme stop band ripple
C	Gradual passband rolloff with minimal stop band ripple
D	Extremely sharp cutoff with one or more notches in the stop band

34. - E7D15

What is the purpose of a step-start circuit in a high-voltage power supply?

Select	Answer
A	To compensate for variations of the incoming line voltage
B	To allow for remote control of the power supply
C	To allow the filter capacitors to charge gradually
D	To provide a dual-voltage output for reduced power applications

35. - E7E04

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

Select	Answer
A	By driving a product detector with a DSB signal
B	By using a loop modulator followed by a mixer
C	By using a balanced modulator followed by a filter
D	By using a reactance modulator followed by a mixer

36. - E7F02

What kind of digital signal processing audio filter is used to remove unwanted noise from a received SSB signal?

Select	Answer
A	An adaptive filter
B	A crystal-lattice filter
C	A Hilbert-transform filter
D	A phase-inverting filter

37. - E7G11

What absolute voltage gain can be expected from the circuit in Figure E7-3 when R1 is 3300 ohms and RF is 47 kilohms?

Select	Answer
A	7
B	14
C	28
D	0.07

38. - E7H05

How is positive feedback supplied in a Pierce oscillator?

Select	Answer
A	Through link coupling
B	Through a tapped coil
C	Through a quartz crystal
D	Through a neutralizing capacitor

39. - E8A09

How many different input levels can be encoded by an analog-to-digital converter with 8-bit resolution?

Select	Answer
A	8
B	256
C	8 multiplied by the gain of the input amplifier
D	256 divided by the gain of the input amplifier

40. - E8B10

What is frequency division multiplexing?

Select	Answer
A	The transmitted signal jumps from band to band at a predetermined rate
B	The transmitted signal is divided into packets of information
C	Two or more information streams are merged into a baseband, which then modulates the transmitter
D	Two or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter

41. - E8C04

What technique minimizes the bandwidth of a PSK31 signal?

Select	Answer
A	Zero-sum character encoding
B	Reed-Solomon character encoding
C	Use of sinusoidal data pulses
D	Use of trapezoidal data pulses

42. - E8D05

What is the most common method of reducing key clicks?

Select	Answer
A	Increase keying waveform rise and fall times
B	Low-pass filters at the transmitter output
C	High-pass filters at the transmitter output
D	Reduce keying waveform rise and fall times

43. - E9A08

What is antenna bandwidth?

Select	Answer
A	The angle formed between two imaginary lines drawn through the element ends
B	The frequency range over which an antenna satisfies a performance requirement
C	The angle between the half-power radiation points
D	Antenna length divided by the number of elements

44. - E9B05

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

Select	Answer
A	Radiation resistance
B	Polarization
C	Azimuth
D	Elevation

45. - E9C10

Which of the following describes a Zepp antenna?

Select	Answer
A	An end-fed dipole antenna
B	A dipole constructed from zip cord
C	A vertical array capable of quickly changing the direction of maximum radiation by changing phasing lines
D	An omni-directional antenna commonly used for satellite communications

46. - E9D07

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

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

47. - E9E05

How must an antenna's driven element be tuned to use a hairpin matching system?

Select	Answer
A	The driven element reactance must be capacitive
B	The driven element resonance must be lower than the operating frequency
C	The driven element radiation resistance must be higher than the characteristic impedance of the transmission line
D	The driven element reactance must be inductive

48. - E9F02

Which of the following has the biggest effect on the velocity factor of a transmission line?

Select	Answer
A	The termination impedance
B	The line length
C	The center conductor resistivity
D	Dielectric materials used in the line

49. - E9G08

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

Select	Answer
A	Reassigning resistance values with regard to the reactance axis
B	Reassigning reactance values with regard to the resistance axis
C	Reassigning impedance values with regard to the prime center
D	Reassigning prime center with regard to the reactance axis

50. - E9H10

How can the output voltage of a multiple-turn receiving loop antenna be increased?

Select	Answer
A	By increasing the number of turns and/or the area
B	By utilizing high impedance wire for the coupling loop
C	By winding adjacent turns in opposing directions
D	By reducing the permeability of the loop shield

Figure E7-3

Figure E9-2