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 the displayed frequency is within the 20 meter band
B	Yes, because you were not the station calling CQ
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. - E1B01

Which of the following constitutes a spurious emission?

Select	Answer
A	Any transmitted signal that unintentionally interferes with another licensed radio station
B	An amateur station transmission made at random without the proper call sign identification
C	A signal transmitted to prevent its detection by any station other than the intended recipient
D	An emission outside its necessary bandwidth that can be reduced or eliminated without affecting the information transmitted

3. - E1C02

What is meant by automatic control of a station?

Select	Answer
A	Remotely controlling a station's antenna pattern through a directional control link
B	The use of a control link between a control point and a locally controlled station
C	The use of devices and procedures for control so that the control operator does not have to be present at a control point
D	A station operating with its output power controlled automatically

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 located more than 50 km above the Earth's surface
C	An amateur station that transmits communications to initiate, modify or terminate functions of a space station
D	An amateur station that transmits telemetry consisting of measurements of upper atmosphere

5. - E1E03

What is a Volunteer Examiner Coordinator?

Select	Answer
A	A person who has volunteered to administer amateur operator license examinations
B	The person who has entered into an agreement with the FCC to be the VE session manager
C	A person who has volunteered to prepare amateur operator license examinations
D	An organization that has entered into an agreement with the FCC to coordinate amateur operator license examinations

6. - E1F03

Under what circumstances may a dealer sell an external RF power amplifier capable of operation below 144 MHz if it has not been granted FCC certification?

Select	Answer
A	The equipment dealer assembled it from a kit
B	It was purchased in used condition from an amateur operator and is sold to another amateur operator for use at that operator's station
C	It was imported from a manufacturer in a country that does not require certification of RF power amplifiers
D	It was imported from a manufacturer in another country and was certificated by that country's government

7. - E2A03

What is the orbital period of an Earth satellite?

Select	Answer
A	The time it takes for a satellite to travel from perigee to apogee
B	The point of maximum height of a satellite's orbit
C	The point of minimum height of a satellite's orbit
D	The time it takes for a satellite to complete one revolution around the Earth

8. - E2B16

Which is a video standard used by North American Fast Scan ATV stations?

Select	Answer
A	PAL
B	NTSC
C	DRM
D	Scottie

9. - E2C05

What is the function of a DX QSL Manager?

Select	Answer
A	To run a net to allow many stations to contact a rare DX station
B	To handle the receiving and sending of confirmation cards for a DX station
C	To allocate frequencies for DXpeditions
D	To relay calls to and from a DX station

10. - E2D11

Which of the following data are used by the APRS network to communicate your location?

Select	Answer
A	Polar coordinates
B	Radio direction finding spectrum analysis
C	Time and frequency
D	Latitude and longitude

11. - E2E01

Which type of modulation is common for data emissions below 30 MHz?

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

12. - E3A07

Atmospheric ducts capable of propagating microwave signals often form over what geographic feature?

Select	Answer
A	Mountain ranges
B	Bodies of water
C	Forests
D	Urban areas

13. - E3B10

What is the cause of gray-line propagation?

Select	Answer
A	At twilight and sunrise, D-layer absorption is low while E-layer and F-layer propagation remains high
B	At mid-afternoon, the Sun heats the ionosphere decreasing radio wave refraction and the MUF
C	At midday, the Sun super heats the ionosphere causing increased refraction of radio waves
D	In darkness, solar absorption drops greatly while atmospheric ionization remains steady

14. - E3C13

What type of polarization is best for ground-wave propagation?

Select	Answer
A	Elliptical
B	Circular
C	Horizontal
D	Vertical

15. - E4A01

Which of the following parameter determines the bandwidth of a digital or computer-based oscilloscope?

Select	Answer
A	Sampling rate
B	Input capacitance
C	Sample resolution
D	Input impedance

16. - E4B02

What is an advantage of using a bridge circuit to measure impedance?

Select	Answer
A	It is very precise in obtaining a signal null
B	It can display results directly in Smith chart format
C	It provides an excellent match under all conditions
D	It is relatively immune to drift in the signal generator source

17. - E4C14

What transmit frequency might generate an image response signal in a receiver tuned to 14.300 MHz and which uses a 455 kHz IF frequency?

Select	Answer
A	14.445 MHz
B	13.845 MHz
C	15.210 MHz
D	14.755 MHz

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

19. - E4E06

What is a major cause of atmospheric static?

Select	Answer
A	Geomagnetic storms
B	Meteor showers
C	Solar radio frequency emissions
D	Thunderstorms

20. - E5A02

What is resonance in an electrical circuit?

Select	Answer
A	The highest frequency that will pass current
B	The frequency at which the capacitive reactance equals the inductive reactance
C	The lowest frequency that will pass current
D	The frequency at which the reactive impedance equals the resistive impedance

21. - E5B13

What letter is commonly used to represent susceptance?

Select	Answer
A	B
B	G
C	Y
D	X

22. - E5C07

What is a vector?

Select	Answer
A	The inverse of the tangent function
B	A quantity with both magnitude and an angular component
C	The value of a quantity that changes over time
D	The inverse of the sine function

23. - E5D01

What is the result of skin effect?

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

24. - E6A01

In what application is gallium arsenide used as a semiconductor material in preference to germanium or silicon?

Select	Answer
A	In high-power audio circuits
B	In microwave circuits
C	In very low frequency RF circuits
D	In high-current rectifier circuits

25. - E6B04

What type of semiconductor device is designed for use as a voltage-controlled capacitor?

Select	Answer
A	Varactor diode
B	Zener diode
C	Silicon-controlled rectifier
D	Tunnel diode

26. - E6C14

What is the primary advantage of using a Programmable Gate Array (PGA) in a logic circuit?

Select	Answer
A	All of these choices are correct
B	Complex logic functions can be created in a single integrated circuit
C	A PGA contains its own internal power supply
D	Many similar gates are less expensive than a mixture of gate types

27. - E6D14

Which type of slug material decreases inductance when inserted into a coil?

Select	Answer
A	Ceramic
B	Powdered-iron
C	Brass
D	Ferrite

28. - E6E03

Which of the following materials is likely to provide the highest frequency of operation when used in MMICs?

Select	Answer
A	Silicon dioxide
B	Silicon nitride
C	Gallium nitride
D	Silicon

29. - E6F14

Which of the following is true of LCD displays?

Select	Answer
A	They are hard to view in high ambient light conditions
B	All of these choices are correct
C	They only display alphanumeric symbols
D	They may be hard view through polarized lenses

30. - E7A08

What logical operation does an OR gate perform?

Select	Answer
A	It produces logic "1" at its output if all inputs are logic "0"
B	It produces logic "0" at its output if all inputs are logic "1"
C	It only produces logic "0" at its output when all inputs are logic "1"
D	It produces logic "1" at its output if any or all inputs are logic "1"

31. - E7B08

How can an RF power amplifier be neutralized?

Select	Answer
A	By reducing the driving power
B	By feeding an in-phase component of the output back to the input
C	By increasing the driving power
D	By feeding a 180-degree out-of-phase portion of the output back to the input

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	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
B	Two inductors are in series between the input and output, and a capacitor is connected between the two inductors and ground
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

33. - E7D15

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

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

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 two input frequencies along with their sum and difference frequencies
C	The sum, difference and square root of the input frequencies
D	1.414 and 0.707 times the input frequency

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

36. - E7G02

What is the effect of ringing in a filter?

Select	Answer
A	An echo caused by a long time delay
B	Partial cancellation of the signal over a range of frequencies
C	A reduction in high frequency response
D	Undesired oscillations added to the desired signal

37. - E7H14

What is a phase-locked loop circuit?

Select	Answer
A	An electronic servo loop consisting of a phase detector, a low-pass filter, a voltage-controlled oscillator, and a stable reference oscillator
B	An electronic circuit consisting of a precision push-pull amplifier with a differential input
C	An electronic servo loop consisting of a ratio detector, reactance modulator, and voltage-controlled oscillator
D	An electronic circuit also known as a monostable multivibrator

38. - 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	All of these choices are correct
C	Immunity to out of sequence coding reduces spurious responses
D	Very low power consumption decreases frequency drift

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	1/3
B	2000
C	6000
D	3

40. - E8C09

Which is the name of a digital code where each preceding or following character changes by only one bit?

Select	Answer
A	Binary Coded Decimal Code
B	Excess 3 code
C	Extended Binary Coded Decimal Interchange Code
D	Gray code

41. - E8D11

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

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

42. - E9A06

How does the beamwidth of an antenna vary as the gain is increased?

Select	Answer
A	It increases geometrically
B	It decreases
C	It is essentially unaffected
D	It increases arithmetically

43. - E9B02

In the antenna radiation pattern shown in Figure E9-1, what is the front-to-back ratio?

Select	Answer
A	18 dB
B	36 dB
C	24 dB
D	14 dB

44. - E9C15

How does the radiation pattern of a horizontally polarized 3-element beam antenna vary with its height above ground?

Select	Answer
A	The main lobe takeoff angle decreases with increasing height
B	The horizontal beam width increases with height
C	The horizontal beam width decreases with height
D	The main lobe takeoff angle increases with increasing height

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	No change occurs
C	It becomes flat
D	It is decreased

46. - E9E05

How must the driven element in a 3-element Yagi be tuned to use a hairpin matching system?

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

47. - E9F08

What is the term for the ratio of the actual speed at which a signal travels through a transmission line to the speed of light in a vacuum?

Select	Answer
A	Velocity factor
B	Surge impedance
C	Standing wave ratio
D	Characteristic impedance

48. - E9G10

What do the arcs on a Smith chart represent?

Select	Answer
A	Frequency
B	Points with constant resistance
C	Points with constant reactance
D	SWR

49. - E9H04

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

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

50. - E0A10

What toxic material may be present in some electronic components such as high voltage capacitors and transformers?

Select	Answer
A	Polychlorinated Biphenyls
B	Polytetrafluroethylene
C	Polymorphic silicon
D	Polyethylene

Figure E9-1