US Amateur Radio - Amateur Extra (Element 4, 2016-2020) Practice Test

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1. - E1A10

If an amateur station is installed aboard a ship or aircraft, what condition must be met before the station is operated?

Select	Answer
A	Its operation must be approved by the master of the ship or the pilot in command of the aircraft
B	The amateur operator must have an FCC Marine or Aircraft endorsement on his or her amateur license
C	The amateur station operator must agree not to transmit when the main radio of the ship or aircraft is in use
D	The amateur station must have a power supply that is completely independent of the main ship or aircraft power supply

2. - E1B10

What frequencies are authorized to an amateur station operating under RACES rules?

Select	Answer
A	All amateur service frequencies authorized to the control operator
B	Specific segments in the amateur service MF, HF, VHF and UHF bands
C	Military Auxiliary Radio System (MARS) channels
D	Specific local government channels

3. - E1C13

Which of the following is required in order to operate in accordance with CEPT rules in foreign countries where permitted?

Select	Answer
A	You must bring a copy of FCC Public Notice DA 11-221
B	The U.S. embassy must approve of your operation
C	You must identify in the official language of the country in which you are operating
D	You must append "/CEPT" to your call sign

4. - E1D03

What is a telecommand station in the amateur satellite service?

Select	Answer
A	An amateur station located on the Earth's surface for communication with other Earth stations by means of Earth satellites
B	An amateur station that transmits communications to initiate, modify or terminate functions of a space station
C	An amateur station that transmits telemetry consisting of measurements of upper atmosphere
D	An amateur station located more than 50 km above the Earth's surface

5. - E1E14

For which types of out-of-pocket expenses do the Part 97 rules state that VEs and VECs may be reimbursed?

Select	Answer
A	Providing amateur operator license examination preparation training materials
B	No expenses are authorized for reimbursement
C	Teaching an amateur operator license examination preparation course
D	Preparing, processing, administering and coordinating an examination for an amateur radio license

6. - E1F02

What privileges are authorized in the U.S. to persons holding an amateur service license granted by the Government of Canada?

Select	Answer
A	All privileges of the Extra Class license
B	Full privileges, up to and including those of the Extra Class License, on the 80, 40, 20, 15, and 10 meter bands
C	None, they must obtain a U.S. license
D	The operating terms and conditions of the Canadian amateur service license, not to exceed U.S. Extra Class privileges

7. - E2A05

What do the letters in a satellite's mode designator specify?

Select	Answer
A	Power limits for uplink and downlink transmissions
B	The uplink and downlink frequency ranges
C	The polarization of uplink and downlink signals
D	The location of the ground control station

8. - E2B14

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

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

9. - E2C13

What indicator is required to be used by U.S.-licensed operators when operating a station via remote control where the transmitter is located in the U.S.?

Select	Answer
A	The ARRL section of the remote station
B	No additional indicator is required
C	/ followed by the USPS two letter abbreviation for the state in which the remote station is located
D	/R# where # is the district of the remote station

10. - E2D03

Which of the following digital modes is especially useful for EME communications?

Select	Answer
A	JT65
B	PACTOR III
C	FSK441
D	Olivia

11. - E2E07

What is the typical bandwidth of a properly modulated MFSK16 signal?

Select	Answer
A	31 Hz
B	316 Hz
C	550 Hz
D	2.16 kHz

12. - E3A11

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

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

13. - E3B07

Which of the following could account for hearing an echo on the received signal of a distant station?

Select	Answer
A	High D layer absorption
B	Receipt of a signal by more than one path
C	Meteor scatter
D	Transmit frequency is higher than the MUF

14. - 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	Sporadic-E
B	Transequatorial propagation
C	Polar paths
D	NVIS

15. - E4A04

What determines the upper frequency limit for a computer soundcard-based oscilloscope program?

Select	Answer
A	Amount of memory on the soundcard
B	Q of the interface of the interface circuit
C	Analog-to-digital conversion speed of the soundcard
D	All of these choices are correct

16. - E4B08

Which of the following is a characteristic of a good DC voltmeter?

Select	Answer
A	Low impedance input
B	Low reluctance input
C	High impedance input
D	High reluctance input

17. - E4C05

What does a value of -174 dBm/Hz represent with regard to the noise floor of a receiver?

Select	Answer
A	The theoretical noise at the input of a perfect receiver at room temperature
B	The minimum detectable signal as a function of receive frequency
C	The noise figure of a 1 Hz bandwidth receiver
D	The galactic noise contribution to minimum detectable signal

18. - E4D06

What is the term for unwanted signals generated by the mixing of two or more signals?

Select	Answer
A	Intermodulation interference
B	Amplifier desensitization
C	Adjacent channel interference
D	Neutralization

19. - E4E03

Which of the following signals might a receiver noise blanker be able to remove from desired signals?

Select	Answer
A	Signals which are constant at all IF levels
B	Signals which have a sharply peaked frequency distribution
C	Signals which appear at one IF but not another
D	Signals which appear across a wide bandwidth

20. - E5A10

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

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

21. - E5B07

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 500 ohms, R is 1 kilohm, and XL is 250 ohms?

Select	Answer
A	68.2 degrees with the voltage leading the current
B	14.0 degrees with the voltage lagging the current
C	14.0 degrees with the voltage leading the current
D	68.2 degrees with the voltage lagging the current

22. - E5C17

Which point on Figure E5-2 best represents the impedance of a series circuit consisting of a 300 ohm resistor, a 0.64-microhenry inductor and an 85-picofarad capacitor at 24.900 MHz?

Select	Answer
A	Point 1
B	Point 3
C	Point 8
D	Point 5

23. - E5D01

What is the result of skin effect?

Select	Answer
A	As frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface
B	As frequency decreases, RF current flows in a thinner layer of the conductor, closer to the surface
C	Thermal effects on the surface of the conductor decrease the impedance
D	Thermal effects on the surface of the conductor increase the impedance

24. - E6A17

What are the names of the three terminals of a field-effect transistor?

Select	Answer
A	Gate 1, gate 2, drain
B	Emitter, base, collector
C	Gate, drain, source
D	Emitter, base 1, base 2

25. - E6B01

What is the most useful characteristic of a Zener diode?

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

26. - E6C06

Why do CMOS digital integrated circuits have high immunity to noise on the input signal or power supply?

Select	Answer
A	The input switching threshold is about one-half the power supply voltage
B	Input signals are stronger
C	The input switching threshold is about two times the power supply voltage
D	Larger bypass capacitors are used in CMOS circuit design

27. - E6D08

What is one reason for using powdered-iron cores rather than ferrite cores in an inductor?

Select	Answer
A	Powdered-iron cores use smaller diameter wire for the same inductance
B	Powdered-iron cores generally require fewer turns to produce a given inductance
C	Powdered-iron cores generally have greater initial permeability
D	Powdered-iron cores generally maintain their characteristics at higher currents

28. - E6E07

Which of the following is typically used to construct a MMIC-based microwave amplifier?

Select	Answer
A	Point-to-point construction
B	Ground-plane construction
C	Microstrip construction
D	Wave-soldering construction

29. - E6F03

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

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

30. - E7A07

What logical operation does a NAND gate perform?

Select	Answer
A	It produces logic "0" at its output only when all inputs are logic "0"
B	It produces logic "1" at its output only when all inputs are logic "1"
C	It produces logic "0" at its output only when all inputs are logic "1"
D	It produces logic "0" at its output if some but not all inputs are logic "1"

31. - E7B17

Why are odd-order rather than even-order intermodulation distortion products of concern in linear power amplifiers?

Select	Answer
A	Because they maintain the sidebands, thus causing multiple duplicate signals
B	Because they are relatively far in frequency from the desired signal
C	Because they invert the sidebands causing distortion
D	Because they are relatively close in frequency to the desired signal

32. - E7C15

What is a crystal lattice filter?

Select	Answer
A	A filter with narrow bandwidth and steep skirts made using quartz crystals
B	A filter with wide bandwidth and shallow skirts made using quartz crystals
C	An audio filter made with four quartz crystals that resonate at 1kHz intervals
D	A power supply filter made with interlaced quartz crystals

33. - E7D06

What is the purpose of Q1 in the circuit shown in Figure E7-3?

Select	Answer
A	It increases the current-handling capability of the regulator
B	It provides negative feedback to improve regulation
C	It provides a constant load for the voltage source
D	It provides D1 with current

34. - E7E08

What are the principal frequencies that appear at the output of a mixer circuit?

Select	Answer
A	Two and four times the original frequency
B	The sum, difference and square root of the input frequencies
C	1.414 and 0.707 times the input frequency
D	The two input frequencies along with their sum and difference frequencies

35. - E7F07

What function can a Fast Fourier Transform perform?

Select	Answer
A	Converting analog signals to digital form
B	Converting digital signals to analog form
C	Converting 8-bit data to 16 bit data
D	Converting digital signals from the time domain to the frequency domain

36. - E7G06

Which of the following is the most appropriate use of an op-amp active filter?

Select	Answer
A	As a high-pass filter used to block RFI at the input to receivers
B	As an audio filter in a receiver
C	As a low-pass filter used between a transmitter and a transmission line
D	For smoothing power supply output

37. - E7H11

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

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

38. - E8A04

What is "dither" with respect to analog to digital converters?

Select	Answer
A	An abnormal condition where the converter cannot settle on a value to represent the signal
B	An error caused by irregular quantization step size
C	A small amount of noise added to the input signal to allow more precise representation of a signal over time
D	A method of decimation by randomly skipping samples

39. - 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	2000
B	6000
C	1/3
D	3

40. - E8C03

When performing phase shift keying, why is it advantageous to shift phase precisely at the zero crossing of the RF carrier?

Select	Answer
A	All of these choices are correct
B	It is easier to demodulate with a conventional, non-synchronous detector
C	This results in the least possible transmitted bandwidth for the particular mode
D	It improves carrier suppression

41. - E8D03

How does the spread spectrum technique of frequency hopping work?

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

42. - E9A05

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

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

43. - E9B08

How can the approximate beam-width in a given plane of a directional antenna be determined?

Select	Answer
A	Measure the ratio of the signal strengths of the radiated power lobes from the front and side of the antenna
B	Note the two points where the signal strength of the antenna is 3 dB less than maximum and compute the angular difference
C	Measure the ratio of the signal strengths of the radiated power lobes from the front and rear of the antenna
D	Draw two imaginary lines through the ends of the elements and measure the angle between the lines

44. - E9C04

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

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

45. - E9D01

How does the gain of an ideal parabolic dish antenna change when the operating frequency is doubled?

Select	Answer
A	Gain is multiplied by 0.707
B	Gain increases by 3 dB
C	Gain increases by 6 dB
D	Gain does not change

46. - E9E10

Which of these choices is an effective way to match an antenna with a 100 ohm feed point impedance to a 50 ohm coaxial cable feed line?

Select	Answer
A	Insert a 1/2 wavelength piece of 300 ohm twin-lead in series between the antenna terminals and the 50 ohm feed cable
B	Connect 1/2 wavelength shorted stub of 75 ohm cable in parallel with the 50 ohm cable where it attaches to the antenna
C	Connect a 1/4-wavelength open stub of 300 ohm twin-lead in parallel with the coaxial feed line where it connects to the antenna
D	Insert a 1/4-wavelength piece of 75 ohm coaxial cable transmission line in series between the antenna terminals and the 50 ohm feed cable

47. - 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	The same as the characteristic impedance of the line
C	The same as the input impedance to the final generator stage
D	A capacitive reactance

48. - E9G07

On the Smith chart shown in Figure E9-3, what is the only straight line shown?

Select	Answer
A	The resistance axis
B	The current axis
C	The reactance axis
D	The voltage axis

49. - E9H06

What is the triangulation method of direction finding?

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

50. - E0A08

What does SAR measure?

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

Figure E5-2

Figure E7-3

Figure E9-3