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

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1. - E0A08

What does SAR measure?

Select	Answer
A	The rate at which RF energy is absorbed by the body
B	The rate of RF energy reflected from stationary terrain
C	Signal Amplification Rating
D	Synthetic Aperture Ratio of the human body

2. - E1A07

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

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

3. - E1B03

Within what distance must an amateur station protect an FCC monitoring facility from harmful interference?

Select	Answer
A	3 miles
B	10 miles
C	1 mile
D	30 miles

4. - E1C03

How do the control operator responsibilities of a station under automatic control differ from one under local control?

Select	Answer
A	Under local control a control operator is not required to be present at a control point
B	Under automatic control there is no control operator
C	Under automatic control the control operator is not required to be present at the control point
D	Under local control there is no control operator

5. - E1D10

Which amateur stations are eligible to be telecommand stations of space stations (subject to the privileges of the class of operator license held by the control operator of the station)?

Select	Answer
A	Any amateur station designated by NASA
B	All these choices are correct
C	Any amateur station so designated by the space station licensee
D	Any amateur station so designated by the ITU

6. - E1E12

What must the VE team do with the application form if the examinee does not pass the exam?

Select	Answer
A	Destroy the application form
B	Maintain the application form with the VEC's records
C	Return the application document to the examinee
D	Send the application form to the FCC and inform the FCC of the grade

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	420 MHz - 430 MHz
C	222 MHz - 223 MHz
D	440 MHz - 450 MHz

8. - E2A04

What is meant by the term mode? as applied to an amateur radio satellite?

Select	Answer
A	The satellite's uplink and downlink frequency bands
B	The satellite's orientation with respect to the Earth
C	Whether the satellite is in a low earth or geostationary orbit
D	Whether the satellite is in a polar or equatorial orbit

9. - E2B02

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

Select	Answer
A	1080
B	30
C	60
D	525

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	Repeater contacts between U.S. club members
C	Special event contacts between stations in the U.S.
D	Contacts using tactical call signs

11. - E2D06

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

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

12. - E2E01

Which of the following types of modulation is common for data emissions below 30 MHz?

Select	Answer
A	FSK
B	Pulse modulation
C	DTMF tones modulating an FM signal
D	Spread spectrum

13. - E3A09

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

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

14. - E3B09

At what time of year is sporadic E propagation most likely to occur?

Select	Answer
A	Around the equinoxes, especially the spring equinox
B	Around the equinoxes, especially the fall equinox
C	Around the solstices, especially the summer solstice
D	Around the solstices, especially the winter solstice

15. - E3C03

Which of the following signal paths is most likely to experience high levels of absorption when the A index or K index is elevated?

Select	Answer
A	Polar
B	Sporadic E
C	Transequatorial
D	NVIS

16. - E4A09

Which of the following is good practice when using an oscilloscope probe?

Select	Answer
A	Keep the signal ground connection of the probe as short as possible
B	Never use a high-impedance probe to measure a low-impedance circuit
C	All these choices are correct
D	Never use a DC-coupled probe to measure an AC circuit

17. - E4B10

Which of the following methods measures intermodulation distortion in an SSB transmitter?

Select	Answer
A	Modulate the transmitter using two RF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
B	Modulate the transmitter using two AF signals having harmonically related frequencies and observe the RF output with a peak reading wattmeter
C	Modulate the transmitter using two AF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
D	Modulate the transmitter using two RF signals having harmonically related frequencies and observe the RF output with a logic analyzer

18. - E4C13

How does a narrow-band roofing filter affect receiver performance?

Select	Answer
A	It improves sensitivity by reducing front end noise
B	It improves intelligibility by using low Q circuitry to reduce ringing
C	All these choices are correct
D	It improves dynamic range by attenuating strong signals near the receive frequency

19. - E4D02

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

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

20. - E4E09

What undesirable effect can occur when using an IF noise blanker?

Select	Answer
A	The audio frequency bandwidth of the received signal might be compressed
B	Nearby signals may appear to be excessively wide even if they meet emission standards
C	Received audio in the speech range might have an echo effect
D	FM signals can no longer be demodulated

21. - E5A06

What is the magnitude of the circulating current within the components of a parallel LC circuit at resonance?

Select	Answer
A	It equals 1 divided by the quantity 2 times pi, multiplied by the square root of inductance L multiplied by capacitance C
B	It is at a minimum
C	It is at a maximum
D	It equals 2 multiplied by pi, multiplied by frequency, multiplied by inductance

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	14 degrees with the voltage lagging the current
B	14 degrees with the voltage leading the current
C	76 degrees with the voltage lagging the current
D	76 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 3
B	Point 1
C	Point 7
D	Point 8

24. - E5D10

How can the true power be determined in an AC circuit where the voltage and current are out of phase?

Select	Answer
A	By multiplying the reactive power by the power factor
B	By multiplying the apparent power by the power factor
C	By dividing the reactive power by the power factor
D	By dividing the apparent power by the power factor

25. - E6A10

In Figure E6-1, what is the schematic symbol for an N-channel dual-gate MOSFET?

Select	Answer
A	4
B	6
C	5
D	2

26. - E6B11

What is used to control the attenuation of RF signals by a PIN diode?

Select	Answer
A	Capacitance of an RF coupling capacitor
B	Forward DC bias current
C	A sub-harmonic pump signal
D	Reverse voltage larger than the RF signal

27. - E6C08

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

Select	Answer
A	2
B	4
C	1
D	3

28. - E6D13

What is the primary cause of inductor self-resonance?

Select	Answer
A	Non-linear core hysteresis
B	The skin effect
C	Inter-turn capacitance
D	Inductive kickback

29. - E6E05

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

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

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. - E7A02

What is the function of a decade counter?

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

32. - E7B13

Which of the following describes an emitter follower (or common collector) amplifier?

Select	Answer
A	An OR circuit with only one emitter used for output
B	A two-transistor amplifier with the emitters sharing a common bias resistor
C	An amplifier with a low impedance output that follows the base input voltage
D	A differential amplifier with both inputs fed to the emitter of the input transistor

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

34. - E7D03

What device is typically used as a stable voltage reference in a linear voltage regulator?

Select	Answer
A	An SCR
B	A tunnel diode
C	A Zener diode
D	A varactor diode

35. - E7E05

What circuit is added to an FM transmitter to boost the higher audio frequencies?

Select	Answer
A	A heterodyne enhancer
B	A de-emphasis network
C	A heterodyne suppressor
D	A pre-emphasis network

36. - E7F03

What type of digital signal processing filter is used to generate an SSB signal?

Select	Answer
A	A notch filter
B	An elliptical filter
C	A Hilbert-transform filter
D	An adaptive filter

37. - E7G06

What is the gain-bandwidth of an operational amplifier?

Select	Answer
A	The gain of the amplifier at a filter's cutoff frequency
B	The frequency at which the open-loop gain of the amplifier equals one
C	The maximum frequency for a filter circuit using that type of amplifier
D	The frequency at which the amplifier's offset voltage is zero

38. - E7H01

What are three oscillator circuits used in amateur radio equipment?

Select	Answer
A	Taft, Pierce and negative feedback
B	Colpitts, Hartley and Pierce
C	Pierce, Fenner and Beane
D	Taft, Hartley and Pierce

39. - E8A09

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

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

40. - E8B04

What is the modulation index of an FM-phone signal having a maximum carrier deviation of plus or minus 6 kHz when modulated with a 2 kHz modulating frequency?

Select	Answer
A	6000
B	2000
C	3
D	1/3

41. - E8C10

How may data rate be increased without increasing bandwidth?

Select	Answer
A	Using forward error correction
B	Using a more efficient digital code
C	It is impossible
D	Increasing analog-to-digital conversion resolution

42. - E8D11

What is one advantage of using ASCII code for data communications?

Select	Answer
A	It uses one character as a shift code to send numeric and special characters
B	It is possible to transmit both upper and lower case text
C	It includes built-in error correction features
D	It contains fewer information bits per character than any other code

43. - E9A10

Which of the following improves the efficiency of a ground-mounted quarter-wave vertical antenna?

Select	Answer
A	Isolating the coax shield from ground
B	All these choices are correct
C	Installing a radial system
D	Shortening the radiating element

44. - E9B11

What is a disadvantage of decreasing the number of wire segments in an antenna model below 10 segments per half-wavelength?

Select	Answer
A	The resulting design will favor radiation of harmonic energy
B	The antenna will become mechanically unstable
C	The computed feed point impedance may be incorrect
D	Ground conductivity will not be accurately modeled

45. - E9C01

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed 180 degrees out of phase?

Select	Answer
A	Cardioid
B	Omni-directional
C	A figure-8 broadside to the axis of the array
D	A figure-8 oriented along the axis of the array

46. - E9D12

Which of the following would provide the best RF ground for your station?

Select	Answer
A	An electrically short connection to a metal water pipe
B	An electrically short connection to 3 or 4 interconnected ground rods via a series RF choke
C	An electrically short connection to 3 or 4 interconnected ground rods driven into the Earth
D	A 50-ohm resistor connected to ground

47. - E9E04

What is the purpose of the series capacitor in a gamma-type antenna matching network?

Select	Answer
A	To provide DC isolation between the feed line and the antenna
B	To transform the antenna impedance to a higher value
C	To provide a rejection notch that prevents the radiation of harmonics
D	To cancel the inductive reactance of the matching network

48. - E9F02

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

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

49. - E9G09

What third family of circles is often added to a Smith chart during the process of solving problems?

Select	Answer
A	Standing wave ratio circles
B	Coaxial-length circles
C	Antenna-length circles
D	Radiation-pattern circles

50. - E9H06

What is the triangulation method of direction finding?

Select	Answer
A	The geometric angles of sky waves from the source are used to determine its position
B	A fixed receiving station plots three headings to the signal source
C	A fixed receiving station uses three different antennas to plot the location of the signal source
D	Antenna headings from several different receiving locations are used to locate the signal source

Figure E5-1

Figure E6-1

Figure E6-3