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

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1. - E1A03

With your transceiver displaying the carrier frequency of phone signals, you hear a station calling CQ on 14.349 MHz USB. Is it legal to return the call using upper sideband on the same frequency?

Select	Answer
A	Yes, because you were not the station calling CQ
B	Yes, because the displayed frequency is within the 20 meter band
C	No, the sideband will extend beyond the band edge
D	No, U.S. stations are not permitted to use phone emissions above 14.340 MHz

2. - E1B04

What must be done before placing an amateur station within an officially designated wilderness area or wildlife preserve, or an area listed in the National Register of Historical Places?

Select	Answer
A	An Environmental Assessment must be submitted to the FCC
B	A letter of intent must be filed with the National Audubon Society
C	A proposal must be submitted to the National Park Service
D	A form FSD-15 must be submitted to the Department of the Interior

3. - E1C11

Which of the following operating arrangements allows an FCC-licensed U.S. citizen to operate in many European countries, and alien amateurs from many European countries to operate in the U.S.?

Select	Answer
A	CEPT agreement
B	ITU reciprocal license
C	All of these choices are correct
D	IARP agreement

4. - E1D07

Which amateur service HF bands have frequencies authorized for space stations?

Select	Answer
A	Only the 40 m, 20 m, 17 m, 15 m and 10 m bands
B	Only the 40 m, 20 m, 17 m, 15 m, 12 m and 10 m bands
C	Only the 40 m, 30 m, 20 m, 15 m, 12 m and 10 m bands
D	All HF bands

5. - E1E05

What is the minimum passing score on amateur operator license examinations?

Select	Answer
A	Minimum passing score of 80%
B	Minimum passing score of 74%
C	Minimum passing score of 77%
D	Minimum passing score of 70%

6. - 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	440 MHz - 450 MHz
B	53 MHz - 54 MHz
C	420 MHz - 430 MHz
D	222 MHz - 223 MHz

7. - E2A07

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

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

8. - E2B03

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

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

9. - E2C03

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

Select	Answer
A	2 m
B	33 cm
C	30 m
D	6 m

10. - E2D03

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

Select	Answer
A	FSK441
B	JT65
C	PACTOR III
D	Olivia

11. - E2E10

Which of these digital modes has the narrowest bandwidth?

Select	Answer
A	300-baud packet
B	170 Hz shift, 45 baud RTTY
C	PSK31
D	MFSK16

12. - E3A14

From the contiguous 48 states, in which approximate direction should an antenna be pointed to take maximum advantage of aurora propagation?

Select	Answer
A	South
B	West
C	North
D	East

13. - E3B04

What is meant by the terms extraordinary and ordinary waves?

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

14. - E3C06

By how much does the VHF/UHF radio horizon distance exceed the geometric horizon?

Select	Answer
A	By approximately twice the distance
B	By approximately 15 percent of the distance
C	By approximately 50 percent of the distance
D	By approximately four times the distance

15. - E4A13

How is the compensation of an oscilloscope probe typically adjusted?

Select	Answer
A	A high frequency sine wave is displayed and the probe is adjusted for maximum amplitude
B	A DC voltage standard is displayed and the probe is adjusted until the displayed voltage is accurate
C	A square wave is displayed and the probe is adjusted until the horizontal portions of the displayed wave are as nearly flat as possible
D	A frequency standard is displayed and the probe is adjusted until the deflection time is accurate

16. - E4B14

What happens if a dip meter is too tightly coupled to a tuned circuit being checked?

Select	Answer
A	Harmonics are generated
B	Intermodulation distortion occurs
C	Cross modulation occurs
D	A less accurate reading results

17. - E4C10

Which of the following is a desirable amount of selectivity for an amateur RTTY HF receiver?

Select	Answer
A	100 Hz
B	300 Hz
C	2400 Hz
D	6000 Hz

18. - E4D04

Which of the following may reduce or eliminate intermodulation interference in a repeater caused by another transmitter operating in close proximity?

Select	Answer
A	A properly terminated circulator at the output of the transmitter
B	A Class D final amplifier
C	A Class C final amplifier
D	A band-pass filter in the feed line between the transmitter and receiver

19. - E4E05

How can noise from an electric motor be suppressed?

Select	Answer
A	By installing a high pass filter in series with the motor's power leads
B	By using a ground-fault current interrupter in the circuit used to power the motor
C	By installing a brute-force AC-line filter in series with the motor leads
D	By installing a bypass capacitor in series with the motor leads

20. - E5A13

What is an effect of increasing Q in a resonant circuit?

Select	Answer
A	Internal voltages and circulating currents increase
B	Fewer components are needed for the same performance
C	Phase shift can become uncontrolled
D	Parasitic effects are minimized

21. - E5B05

What happens to the magnitude of a reactance when it is converted to a susceptance?

Select	Answer
A	It is shifted by 90 degrees
B	The magnitude of the susceptance is the reciprocal of the magnitude of the reactance
C	It is unchanged
D	The sign is reversed

22. - E5C08

What coordinate system is often used to display the phase angle of a circuit containing resistance, inductive and/or capacitive reactance?

Select	Answer
A	Polar coordinates
B	Maidenhead grid
C	Elliptical coordinates
D	Faraday grid

23. - E5D02

Why is it important to keep lead lengths short for components used in circuits for VHF and above?

Select	Answer
A	To avoid unwanted inductive reactance
B	To increase the thermal time constant
C	To maintain component lifetime
D	All of these choices are correct

24. - E6A16

What are the majority charge carriers in N-type semiconductor material?

Select	Answer
A	Holes
B	Free protons
C	Free neutrons
D	Free electrons

25. - E6B08

Which of the following describes a type of semiconductor diode?

Select	Answer
A	Thermionic emission diode
B	Electrolytic rectifier
C	CMOS-field effect
D	Metal-semiconductor junction

26. - E6C03

What is tri-state logic?

Select	Answer
A	Logic devices that utilize ternary math
B	Proprietary logic devices manufactured by Tri-State Devices
C	Logic devices with 0, 1, and high impedance output states
D	Low power logic devices designed to operate at 3 volts

27. - E6D10

What is a primary advantage of using a toroidal core instead of a solenoidal core in an inductor?

Select	Answer
A	Toroidal cores make it easier to couple the magnetic energy into other components
B	Toroidal cores have lower Q characteristics
C	Toroidal cores exhibit greater hysteresis
D	Toroidal cores confine most of the magnetic field within the core material

28. - E6E01

Which of the following is true of a charge-coupled device (CCD)?

Select	Answer
A	It is a CMOS analog-to-digital converter
B	It samples an analog signal and passes it in stages from the input to the output
C	It is used in a battery charger circuit
D	Its phase shift changes rapidly with frequency

29. - E6F03

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

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

30. - E7A07

What logical operation does a NAND gate perform?

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

31. - E7B16

What is the effect of intermodulation products in a linear power amplifier?

Select	Answer
A	Transmission of spurious signals
B	Low efficiency
C	All of these choices are correct
D	Creation of parasitic oscillations

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

33. - E7D15

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

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

34. - E7E10

How does a diode detector function?

Select	Answer
A	By sensing the change of reactance in the diode with respect to frequency
B	By mixing signals with noise in the transition region of the diode
C	By rectification and filtering of RF signals
D	By breakdown of the Zener voltage

35. - E7F10

What aspect of receiver analog-to-digital conversion determines the maximum receive bandwidth of a Direct Digital Conversion SDR?

Select	Answer
A	Sample rate
B	Processor latency
C	Sample width in bits
D	Sample clock phase noise

36. - E7G09

What will be the output voltage of the circuit shown in Figure E7-4 if R1 is 1000 ohms, RF is 10,000 ohms, and 0.23 volts DC is applied to the input?

Select	Answer
A	0.23 volts
B	-2.3 volts
C	-0.23 volts
D	2.3 volts

37. - E7H15

Which of these functions can be performed by a phase-locked loop?

Select	Answer
A	Wide-band AF and RF power amplification
B	Comparison of two digital input signals, digital pulse counter
C	Photovoltaic conversion, optical coupling
D	Frequency synthesis, FM demodulation

38. - E8A08

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

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

39. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

Select	Answer
A	A digital modulation technique using subcarriers at frequencies chosen to avoid intersymbol interference
B	A frequency modulation technique which uses non-harmonically related frequencies
C	A digital mode for narrow band, slow speed transmissions
D	A bandwidth compression technique using Fourier transforms

40. - E8C05

What is the necessary bandwidth of a 13-WPM international Morse code transmission?

Select	Answer
A	Approximately 13 Hz
B	Approximately 52 Hz
C	Approximately 104 Hz
D	Approximately 26 Hz

41. - E8D01

Why are received spread spectrum signals resistant to interference?

Select	Answer
A	If interference is detected by the receiver it will signal the transmitter to change frequencies
B	The receiver is always equipped with a digital blanker
C	Signals not using the spread spectrum algorithm are suppressed in the receiver
D	The high power used by a spread spectrum transmitter keeps its signal from being easily overpowered

42. - E9A05

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

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

43. - E9B06

What is the elevation angle of peak response in the antenna radiation pattern shown in Figure E9-2?

Select	Answer
A	7.5 degrees
B	25 degrees
C	45 degrees
D	75 degrees

44. - E9C05

What is an OCFD antenna?

Select	Answer
A	An eight band dipole antenna using octophase filters
B	A dipole feed approximately 1/3 the way from one end with a 4:1 balun to provide multiband operation
C	A remotely tunable dipole antenna using orthogonally controlled frequency diversity
D	A multiband dipole antenna using one-way circular polarization for frequency diversity

45. - E9D06

What happens to the bandwidth of an antenna as it is shortened through the use of loading coils?

Select	Answer
A	It is increased
B	It becomes flat
C	No change occurs
D	It is decreased

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	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
B	Insert a 1/2 wavelength piece of 300 ohm twin-lead in series between the antenna terminals and the 50 ohm feed cable
C	Connect 1/2 wavelength shorted stub of 75 ohm cable in parallel with the 50 ohm cable where it attaches 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. - E9F12

What impedance does a 1/4 wavelength transmission line present to a generator when the line is open at the far end?

Select	Answer
A	The same as the characteristic impedance of the line
B	Very high impedance
C	The same as the input impedance to the generator
D	Very low impedance

48. - E9G07

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

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

49. - E9H04

What is an advantage of using a shielded loop antenna for direction finding?

Select	Answer
A	It is electro statically balanced against ground, giving better nulls
B	It eliminates tracking errors caused by strong out-of-band signals
C	It automatically cancels ignition noise in mobile installations
D	It allows stations to communicate without giving away their position

50. - E0A07

How may dangerous levels of carbon monoxide from an emergency generator be detected?

Select	Answer
A	By the odor
B	Any ordinary smoke detector can be used
C	Only with a carbon monoxide detector
D	By the yellowish appearance of the gas

Figure E7-4

Figure E9-2

Figure E9-3