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

Logging in (or registering) will help the system to select questions that you need to focus on.

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	No, the sideband will extend beyond the band edge
C	No, U.S. stations are not permitted to use phone emissions above 14.340 MHz
D	Yes, because you were not the station calling CQ

2. - E1B07

What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?

Select	Answer
A	1.0
B	3.0
C	0.5
D	2.0

3. - E1C02

What is meant by automatic control of a station?

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

4. - E1D08

Which VHF amateur service bands have frequencies available for space stations?

Select	Answer
A	6 meters and 2 meters
B	2 meters and 1.25 meters
C	6 meters, 2 meters, and 1.25 meters
D	2 meters

5. - E1E04

Which of the following best describes the Volunteer Examiner accreditation process?

Select	Answer
A	Each General, Advanced and Amateur Extra Class operator is automatically accredited as a VE when the license is granted
B	The prospective VE obtains accreditation from the FCC
C	The amateur operator applying must pass a VE examination administered by the FCC Enforcement Bureau
D	The procedure by which a VEC confirms that the VE applicant meets FCC requirements to serve as an examiner

6. - E1F12

Who may be the control operator of an auxiliary station?

Select	Answer
A	Only General, Advanced or Amateur Extra Class operators
B	Only Amateur Extra Class operators
C	Only Technician, General, Advanced or Amateur Extra Class operators
D	Any licensed amateur operator

7. - E2A07

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

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

8. - E2B07

What is the name of the signal component that carries color information in NTSC video?

Select	Answer
A	Spectral Intensity
B	Luminance
C	Hue
D	Chroma

9. - E2C04

What type of transmission is most often used for a ham radio mesh network?

Select	Answer
A	Multiple Frequency Shift Keying in the 10 GHz band
B	Store and forward on the 440 MHz band
C	Frequency division multiplex in the 24 GHz band
D	Spread spectrum in the 2.4 GHz band

10. - E2D09

Which of these digital modes has the fastest data throughput under clear communication conditions?

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

11. - E2E01

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

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

12. - E3A07

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

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

13. - E3B01

What is transequatorial propagation?

Select	Answer
A	Propagation between two mid-latitude points at approximately the same distance north and south of the magnetic equator
B	Propagation between any two points located on the magnetic equator
C	Propagation between two continents by way of ducts along the magnetic equator
D	Propagation between two stations at the same latitude

14. - E3C09

How does the intensity of an X3 flare compare to that of an X2 flare?

Select	Answer
A	50 percent greater
B	10 percent greater
C	Twice as great
D	Four times as great

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

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. - E4C03

What is the term for the blocking of one FM phone signal by another, stronger FM phone signal?

Select	Answer
A	Desensitization
B	Frequency discrimination
C	Cross-modulation interference
D	Capture effect

18. - E4D02

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

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

19. - E4E09

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

Select	Answer
A	FM signals can no longer be demodulated
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	The audio frequency bandwidth of the received signal might be compressed

20. - E5A04

What is the magnitude of the impedance of a circuit with a resistor, an inductor and a capacitor all in parallel, at resonance?

Select	Answer
A	Approximately equal to inductive reactance
B	Approximately equal to circuit resistance
C	Approximately equal to capacitive reactance
D	Low, as compared to the circuit resistance

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 leading the current
C	14 degrees with the voltage lagging the current
D	76 degrees with the voltage lagging the current

22. - E5C05

What is the name of the diagram used to show the phase relationship between impedances at a given frequency?

Select	Answer
A	Venn diagram
B	Phasor diagram
C	Far field diagram
D	Near field diagram

23. - E5D11

What is the power factor of an R-L circuit having a 60 degree phase angle between the voltage and the current?

Select	Answer
A	1.414
B	0.5
C	0.866
D	1.73

24. - E6A12

Why do many MOSFET devices have internally connected Zener diodes on the gates?

Select	Answer
A	To protect the substrate from excessive voltages
B	To provide a voltage reference for the correct amount of reverse-bias gate voltage
C	To reduce the chance of the gate insulation being punctured by static discharges or excessive voltages
D	To keep the gate voltage within specifications and prevent the device from overheating

25. - E6B03

What special type of diode is capable of both amplification and oscillation?

Select	Answer
A	Point contact
B	Zener
C	Tunnel
D	Junction

26. - E6C11

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

Select	Answer
A	4
B	6
C	2
D	5

27. - E6D04

Which materials are commonly used as a slug core in a variable inductor?

Select	Answer
A	Teflon and Delrin
B	Polystyrene and polyethylene
C	Cobalt and aluminum
D	Ferrite and brass

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
C	Gallium nitride
D	Silicon nitride

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. - E7A09

What logical operation is performed by an exclusive NOR gate?

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

31. - E7B04

Where on the load line of a Class A common emitter amplifier would bias normally be set?

Select	Answer
A	At a point where the load line intersects the zero bias current curve
B	Approximately half-way between saturation and cutoff
C	Where the load line intersects the voltage axis
D	At a point where the bias resistor equals the load resistor

32. - E7C05

Which filter type is described as having ripple in the passband and a sharp cutoff?

Select	Answer
A	A passive op-amp filter
B	An active LC filter
C	A Butterworth filter
D	A Chebyshev filter

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

34. - E7E06

Why is de-emphasis commonly used in FM communications receivers?

Select	Answer
A	For compatibility with transmitters using phase modulation
B	For higher efficiency
C	To remove third-order distortion products
D	To reduce impulse noise reception

35. - E7F04

What is a common method of generating an SSB signal using digital signal processing?

Select	Answer
A	Emulation of quartz crystal filter characteristics
B	Combine signals with a quadrature phase relationship
C	Mixing products are converted to voltages and subtracted by adder circuits
D	A frequency synthesizer removes the unwanted sidebands

36. - E7G12

What is an integrated circuit operational amplifier?

Select	Answer
A	A high-gain, direct-coupled differential amplifier with very high input impedance and very low output impedance
B	A digital audio amplifier whose characteristics are determined by components external to the amplifier
C	A RF amplifier used in the UHF and microwave regions
D	An amplifier used to increase the average output of frequency modulated amateur signals to the legal limit

37. - E7H14

What is a phase-locked loop circuit?

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

38. - E8A03

What type of wave does a Fourier analysis show to be made up of sine waves of a given fundamental frequency plus all of its harmonics?

Select	Answer
A	A cosine wave
B	A square wave
C	A sine wave
D	A sawtooth wave

39. - E8B10

What describes frequency division multiplexing?

Select	Answer
A	Two or more information streams are merged into a baseband, which then modulates the transmitter
B	The transmitted signal jumps from band to band at a predetermined rate
C	The transmitted signal is divided into packets of information
D	Two or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter

40. - E8C07

What is the necessary bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?

Select	Answer
A	5.76 kHz
B	4.8 kHz
C	15.36 kHz
D	9.6 kHz

41. - E8D02

What spread spectrum communications technique uses a high speed binary bit stream to shift the phase of an RF carrier?

Select	Answer
A	Direct sequence
B	Binary phase-shift keying
C	Phase compandored spread spectrum
D	Frequency hopping

42. - E9A11

Which of the following factors determines ground losses for a ground-mounted vertical antenna operating in the 3 MHz to 30 MHz range?

Select	Answer
A	Distance from the transmitter
B	The standing wave ratio
C	Take-off angle
D	Soil conductivity

43. - E9B14

What type of information can be obtained by submitting the details of a proposed new antenna to a modeling program?

Select	Answer
A	SWR vs frequency charts
B	Antenna gain
C	All of these choices are correct
D	Polar plots of the far field elevation and azimuth patterns

44. - E9C12

Which of the following describes an extended double Zepp antenna?

Select	Answer
A	A center fed 1.25 wavelength antenna (two 5/8 wave elements in phase)
B	An end fed folded dipole antenna
C	A wideband vertical antenna constructed from precisely tapered aluminum tubing
D	A portable antenna erected using two push support poles

45. - E9D04

Why should an HF mobile antenna loading coil have a high ratio of reactance to resistance?

Select	Answer
A	To minimize losses
B	To maximize losses
C	To minimize the Q
D	To swamp out harmonics

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

47. - E9F02

Which of the following determines the velocity factor of a transmission line?

Select	Answer
A	The center conductor resistivity
B	Dielectric materials used in the line
C	The line length
D	The termination 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. - E9H07

Why is it advisable to use an RF attenuator on a receiver being used for direction finding?

Select	Answer
A	It compensates for the effects of an isotropic antenna, thereby improving directivity
B	It narrows the bandwidth of the received signal to improve signal to noise ratio
C	It reduces loss of received signals caused by antenna pattern nulls, thereby increasing sensitivity
D	It prevents receiver overload which could make it difficult to determine peaks or nulls

50. - E0A10

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

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

Figure E6-5

Figure E9-3