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

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1. - E1A08

If a station in a message forwarding system inadvertently forwards a message that is in violation of FCC rules, who is primarily accountable for the rules violation?

Select	Answer
A	The control operators of all the stations in the system
B	The control operators of all the stations in the system not authenticating the source from which they accept communications
C	The control operator of the originating station
D	The control operator of the packet bulletin board station

2. - E1B09

Which amateur stations may be operated under RACES rules?

Select	Answer
A	Any FCC-licensed amateur station except a Technician class
B	Only those club stations licensed to Amateur Extra class operators
C	Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served
D	Any FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)

3. - E1C09

Which of these ranges of frequencies is available for an automatically controlled repeater operating below 30 MHz?

Select	Answer
A	29.500 MHz - 29.700 MHz
B	18.110 MHz - 18.168 MHz
C	24.940 MHz - 24.990 MHz
D	10.100 MHz - 10.150 MHz

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

5. - E1E06

Who is responsible for the proper conduct and necessary supervision during an amateur operator license examination session?

Select	Answer
A	The VE session manager
B	The VEC coordinating the session
C	Each administering VE
D	The FCC

6. - E1F01

On what frequencies are spread spectrum transmissions permitted?

Select	Answer
A	Only on amateur frequencies above 50 MHz
B	Only on amateur frequencies above 222 MHz
C	Only on amateur frequencies above 144 MHz
D	Only on amateur frequencies above 420 MHz

7. - E2A09

What do the terms L band and S band specify with regard to satellite communications?

Select	Answer
A	The 2 meter and 70 centimeter bands
B	FM and Digital Store-and-Forward systems
C	Which sideband to use
D	The 23 centimeter and 13 centimeter bands

8. - E2B02

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

Select	Answer
A	60
B	525
C	30
D	1080

9. - E2C08

Which of the following contacts may be confirmed through the U.S. QSL bureau system?

Select	Answer
A	Repeater contacts between U.S. club members
B	Contacts between a U.S. station and a non-U.S. station
C	Special event contacts between stations in the U.S.
D	Contacts using tactical call signs

10. - E2D10

How can an APRS station be used to help support a public service communications activity?

Select	Answer
A	All of these choices are correct
B	An APRS station with a GPS unit can automatically transmit information to show a mobile station's position during the event
C	An APRS station with an emergency medical technician can automatically transmit medical data to the nearest hospital
D	APRS stations with General Personnel Scanners can automatically relay the participant numbers and time as they pass the check points

11. - E2E01

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

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

12. - E3A09

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

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

13. - E3B11

At what time of day is Sporadic-E propagation most likely to occur?

Select	Answer
A	Any time
B	Around sunset
C	Early evening
D	Around sunrise

14. - E3C10

What does the 304A solar parameter measure?

Select	Answer
A	UV emissions at 304 angstroms, correlated to solar flux index
B	The solar emission at 304 GHz, correlated to X-Ray flare levels
C	The solar wind velocity at 304 degrees from the solar equator, correlated to solar activity
D	The ratio of X-Ray flux to radio flux, correlated to sunspot number

15. - E4A09

When using a computer's soundcard input to digitize signals, what is the highest frequency signal that can be digitized without aliasing?

Select	Answer
A	One-half the sample rate
B	One-tenth the sample rate
C	It depends on how the data is stored internally
D	The same as the sample rate

16. - E4B15

Which of the following can be used as a relative measurement of the Q for a series-tuned circuit?

Select	Answer
A	The resonant frequency of the circuit
B	The inductance to capacitance ratio
C	The bandwidth of the circuit's frequency response
D	The frequency shift

17. - E4C15

What is usually the primary source of noise that is heard from an HF receiver with an antenna connected?

Select	Answer
A	Atmospheric noise
B	Receiver front-end noise
C	Induction motor noise
D	Detector noise

18. - E4D09

What is the purpose of the preselector in a communications receiver?

Select	Answer
A	To provide a range of AGC time constants
B	To store often-used frequencies
C	To allow selection of the optimum RF amplifier device
D	To increase rejection of unwanted signals

19. - E4E06

What is a major cause of atmospheric static?

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

20. - E5A15

Which of the following can increase Q for inductors and capacitors?

Select	Answer
A	Higher self-resonant frequency
B	Lower losses
C	Lower reactance
D	Lower self-resonant frequency

21. - 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	14 degrees with the voltage lagging the current
C	76 degrees with the voltage lagging the current
D	14 degrees with the voltage leading the current

22. - E5C04

Which of the following represents a capacitive reactance in polar coordinates?

Select	Answer
A	A positive phase angle
B	A negative real part
C	A negative phase angle
D	A positive real part

23. - 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 dividing the apparent power by the power factor
B	By multiplying the reactive power times the power factor
C	By multiplying the apparent power times the power factor
D	By dividing the reactive power by the power factor

24. - E6A04

What is the name given to an impurity atom that adds holes to a semiconductor crystal structure?

Select	Answer
A	Insulator impurity
B	N-type impurity
C	Acceptor impurity
D	Donor impurity

25. - E6B13

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

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

26. - E6C11

In Figure E6-5, what is the schematic symbol for the NOT operation (inverter)?

Select	Answer
A	6
B	2
C	4
D	5

27. - E6D13

What is the primary cause of inductor self-resonance?

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

28. - E6E05

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

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

29. - E6F06

Which of these materials is affected the most by photoconductivity?

Select	Answer
A	A heavy metal
B	A crystalline semiconductor
C	An ordinary metal
D	A liquid semiconductor

30. - E7A02

What is the function of a decade counter digital IC?

Select	Answer
A	It produces ten output pulses for every input pulse
B	It produces one output pulse for every ten input pulses
C	It adds two decimal numbers together
D	It decodes a decimal number for display on a seven segment LED display

31. - E7B06

Which of the following amplifier types reduces or eliminates even order harmonics?

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

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	Two capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground
D	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

33. - E7D04

Which of the following types of linear voltage regulator usually make the most efficient use of the primary power source?

Select	Answer
A	A series regulator
B	A series current source
C	A shunt current source
D	A shunt regulator

34. - E7E03

How does an analog phase modulator function?

Select	Answer
A	By varying the tuning of a microphone preamplifier to produce AM signals
B	By varying the tuning of an amplifier tank circuit to produce PM signals
C	By varying the tuning of a microphone preamplifier to produce PM signals
D	By varying the tuning of an amplifier tank circuit to produce AM signals

35. - E7F02

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

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

36. - E7G01

What is the typical output impedance of an integrated circuit op-amp?

Select	Answer
A	Very low
B	100 ohms
C	1000 ohms
D	Very high

37. - E7H06

Which of the following oscillator circuits are commonly used in VFOs?

Select	Answer
A	Colpitts and Hartley
B	Pierce and Zener
C	Armstrong and deForest
D	Negative feedback and balanced feedback

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	A method of decimation by randomly skipping samples
C	An error caused by irregular quantization step size
D	A small amount of noise added to the input signal to allow more precise representation of a signal over time

39. - E8B09

What is meant by deviation ratio?

Select	Answer
A	The ratio of the audio modulating frequency to the center carrier frequency
B	The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency
C	The ratio of the carrier center frequency to the audio modulating frequency
D	The ratio of the highest audio modulating frequency to the average audio modulating frequency

40. - E8C09

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

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

41. - E8D11

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

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

42. - E9A15

What is the effective radiated power relative to a dipole of a repeater station with 150 watts transmitter power output, 2 dB feed line loss, 2.2 dB duplexer loss, and 7 dBd antenna gain?

Select	Answer
A	420 watts
B	1977 watts
C	78.7 watts
D	286 watts

43. - E9B11

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

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

44. - 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	A figure-8 oriented along the axis of the array
C	A figure-8 broadside to the axis of the array
D	Omni-directional

45. - E9D02

How can linearly polarized Yagi antennas be used to produce circular polarization?

Select	Answer
A	Stack two Yagis fed 90 degrees out of phase to form an array with the respective elements in parallel planes
B	Stack two Yagis fed in phase to form an array with the respective elements in parallel planes
C	Arrange two Yagis collinear to each other with the driven elements fed 180 degrees out of phase
D	Arrange two Yagis perpendicular to each other with the driven elements at the same point on the boom fed 90 degrees out of phase

46. - E9E07

What term best describes the interactions at the load end of a mismatched transmission line?

Select	Answer
A	Velocity factor
B	Characteristic impedance
C	Dielectric constant
D	Reflection coefficient

47. - E9F14

What impedance does a 1/2 wavelength transmission line present to a generator when the line is shorted at the far end?

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

48. - E9G03

Which of the following is often determined using a Smith chart?

Select	Answer
A	Impedance and SWR values in transmission lines
B	Trigonometric functions
C	Beam headings and radiation patterns
D	Satellite azimuth and elevation bearings

49. - E9H01

When constructing a Beverage antenna, which of the following factors should be included in the design to achieve good performance at the desired frequency?

Select	Answer
A	It must be mounted more than 1 wavelength above ground
B	It should be configured as a four-sided loop
C	Its overall length must not exceed 1/4 wavelength
D	It should be one or more wavelengths long

50. - E0A08

What does SAR measure?

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

Figure E6-5