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

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1. - E1A09

What is the first action you should take if your digital message forwarding station inadvertently forwards a communication that violates FCC rules?

Select	Answer
A	Notify the nearest FCC Field Engineer's office
B	Discontinue forwarding all messages
C	Notify the originating station that the communication does not comply with FCC rules
D	Discontinue forwarding the communication as soon as you become aware of it

2. - E1B06

Which of the following additional rules apply if you are installing an amateur station antenna at a site at or near a public use airport?

Select	Answer
A	No special rules apply if your antenna structure will be less than 300 feet in height
B	You may have to notify the Federal Aviation Administration and register it with the FCC as required by Part 17 of FCC rules
C	You must file an Environmental Impact Statement with the EPA before construction begins
D	You must obtain a construction permit from the airport zoning authority

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	A station operating with its output power controlled automatically
C	The use of a control link between a control point and a locally controlled station
D	The use of devices and procedures for control so that the control operator does not have to be present at a control point

4. - E1D05

What class of licensee is authorized to be the control operator of a space station?

Select	Answer
A	Only Amateur Extra Class
B	All except Technician Class
C	Any class with appropriate operator privileges
D	Only General, Advanced or Amateur Extra Class

5. - E1E01

What is the minimum number of qualified VEs required to administer an Element 4 amateur operator license examination?

Select	Answer
A	3
B	5
C	2
D	4

6. - E1F01

On what frequencies are spread spectrum transmissions permitted?

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

7. - E2A07

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

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

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 frequency
D	Tone amplitude

9. - E2C06

During a VHF/UHF contest, in which band segment would you expect to find the highest level of activity?

Select	Answer
A	In the middle of the band, usually 25 kHz above the national calling frequency
B	At the top of each band, usually in a segment reserved for contests
C	In the weak signal segment of the band, with most of the activity near the calling frequency
D	In the middle of each band, usually on the national calling frequency

10. - E2D08

What type of packet frame is used to transmit APRS beacon data?

Select	Answer
A	Unnumbered Information
B	Acknowledgement
C	Disconnect
D	Connect

11. - E2E03

How is the timing of JT65 contacts organized?

Select	Answer
A	It depends on the lunar phase
B	By exchanging ACK/NAK packets
C	Stations take turns on alternate days
D	Alternating transmissions at 1 minute intervals

12. - E3A01

What is the approximate maximum separation measured along the surface of the Earth between two stations communicating by Moon bounce?

Select	Answer
A	2000 miles, if the Moon is at apogee
B	500 miles, if the Moon is at perigee
C	5000 miles, if the Moon is at perigee
D	12,000 miles, if the Moon is visible by both stations

13. - E3B06

Which of the following amateur bands most frequently provides long-path propagation?

Select	Answer
A	20 meters
B	80 meters
C	6 meters
D	10 meters

14. - E3C12

How does the maximum distance of ground-wave propagation change when the signal frequency is increased?

Select	Answer
A	It decreases
B	It stays the same
C	It peaks at roughly 14 MHz
D	It increases

15. - E4A01

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

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

16. - E4B17

What three test loads are used to calibrate a standard RF vector network analyzer?

Select	Answer
A	50 ohms, 75 ohms, and 90 ohms
B	50 ohms through 1/8 wavelength, 1/4 wavelength, and 1/2 wavelength of coaxial cable
C	Short circuit, open circuit, and 50 ohms
D	Short circuit, open circuit, and resonant circuit

17. - E4C04

How is the noise figure of a receiver defined?

Select	Answer
A	The ratio in dB of the noise generated by the receiver to the theoretical minimum noise
B	The ratio of the noise bandwidth in Hertz to the theoretical bandwidth of a resistive network
C	The ratio of thermal noise to atmospheric noise
D	The ratio of atmospheric noise to phase noise

18. - E4D06

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

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

19. - E4E06

What is a major cause of atmospheric static?

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

20. - E5A05

What is the magnitude of the current at the input of a series RLC circuit as the frequency goes through resonance?

Select	Answer
A	Maximum
B	R/L
C	Minimum
D	L/R

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	14 degrees with the voltage leading the current
B	76 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. - E5C01

Which of the following represents a capacitive reactance in rectangular notation?

Select	Answer
A	+jX
B	-jX
C	Omega
D	X

23. - E5D18

How many watts are consumed in a circuit having a power factor of 0.71 if the apparent power is 500VA?

Select	Answer
A	252 W
B	355 W
C	704 W
D	1.42 mW

24. - E6A14

How does DC input impedance at the gate of a field-effect transistor compare with the DC input impedance of a bipolar transistor?

Select	Answer
A	They are both low impedance
B	An FET has high input impedance; a bipolar transistor has low input impedance
C	They are both high impedance
D	An FET has low input impedance; a bipolar transistor has high input impedance

25. - E6B13

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

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

26. - E6C04

What is the primary advantage of tri-state logic?

Select	Answer
A	More efficient arithmetic operations
B	Ability to connect many device outputs to a common bus
C	Low power consumption
D	High speed operation

27. - E6D17

Why should core saturation of a conventional impedance matching transformer be avoided?

Select	Answer
A	Temporary changes of the core permeability could result
B	Magnetic flux would increase with frequency
C	Harmonics and distortion could result
D	RF susceptance would increase

28. - E6E01

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

Select	Answer
A	Its phase shift changes rapidly with frequency
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	It is a CMOS analog-to-digital converter

29. - E6F02

What happens to the conductivity of a photoconductive material when light shines on it?

Select	Answer
A	It becomes unstable
B	It increases
C	It decreases
D	It stays the same

30. - E7A11

What type of logic defines "1" as a high voltage?

Select	Answer
A	Positive Logic
B	Assertive Logic
C	Negative logic
D	Reverse Logic

31. - E7B15

What is one way to prevent thermal runaway in a bipolar transistor amplifier?

Select	Answer
A	All of these choices are correct
B	Use a resistor in series with the emitter
C	Neutralization
D	Select transistors with high beta

32. - E7C11

Which of the following is the common name for a filter network which is equivalent to two L-networks connected back-to-back with the two inductors in series and the capacitors in shunt at the input and output?

Select	Answer
A	Cascode
B	Omega
C	Pi-L
D	Pi

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 provide a dual-voltage output for reduced power applications
C	To compensate for variations of the incoming line voltage
D	To allow the filter capacitors to charge gradually

34. - E7E06

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

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

35. - E7F14

Which of the following would allow a digital signal processing filter to create a sharper filter response?

Select	Answer
A	Complex phasor representations
B	Higher data rate
C	Double-precision math routines
D	More taps

36. - E7G02

What is the effect of ringing in a filter?

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

37. - E7H04

How is positive feedback supplied in a Colpitts oscillator?

Select	Answer
A	Through a tapped coil
B	Through link coupling
C	Through a neutralizing capacitor
D	Through a capacitive divider

38. - E8A05

What would be the most accurate way of measuring the RMS voltage of a complex waveform?

Select	Answer
A	By using a grid dip meter
B	By measuring the voltage with a D'Arsonval meter
C	By measuring the heating effect in a known resistor
D	By using an absorption wave meter

39. - E8B02

How does the modulation index of a phase-modulated emission vary with RF carrier frequency (the modulated frequency)?

Select	Answer
A	It decreases as the RF carrier frequency increases
B	It does not depend on the RF carrier frequency
C	It varies with the square root of the RF carrier frequency
D	It increases as the RF carrier frequency increases

40. - E8C08

How does ARQ accomplish error correction?

Select	Answer
A	If errors are detected, redundant data is substituted
B	Special polynomial codes provide automatic correction
C	Special binary codes provide automatic correction
D	If errors are detected, a retransmission is requested

41. - E8D01

Why are received spread spectrum signals resistant to interference?

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

42. - E9A10

Which of the following choices is a way to improve the efficiency of a ground-mounted quarter-wave vertical antenna?

Select	Answer
A	Reduce the diameter of the radiating element
B	Install a good radial system
C	Shorten the radiating element
D	Isolate the coax shield from ground

43. - E9B10

What is the principle of a Method of Moments analysis?

Select	Answer
A	A wire is modeled as a series of points, each having a distinct location in space
B	A wire is modeled as a series of segments, each having a distinct value of voltage across it
C	A wire is modeled as a series of segments, each having a uniform value of current
D	A wire is modeled as a single sine-wave current generator

44. - E9C03

What is the radiation pattern of two 1/4 wavelength vertical antennas spaced a 1/2 wavelength apart and fed in phase?

Select	Answer
A	Cardioid
B	A Figure-8 end-fire along the axis of the array
C	Omni-directional
D	A Figure-8 broadside to the axis of the array

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

46. - E9E02

What is the name of an antenna matching system that matches an unbalanced feed line to an antenna by feeding the driven element both at the center of the element and at a fraction of a wavelength to one side of center?

Select	Answer
A	The gamma match
B	The epsilon match
C	The stub match
D	The delta match

47. - E9F07

How does ladder line compare to small-diameter coaxial cable such as RG-58 at 50 MHz?

Select	Answer
A	Lower velocity factor
B	Smaller reflection coefficient
C	Higher SWR
D	Lower loss

48. - E9G06

On the Smith chart shown in Figure E9-3, what is the name for the large outer circle on which the reactance arcs terminate?

Select	Answer
A	Impedance axis
B	Prime axis
C	Reactance axis
D	Polar axis

49. - E9H07

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

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

50. - E0A02

When evaluating RF exposure levels from your station at a neighbor's home, what must you do?

Select	Answer
A	Make sure signals from your station are less than the uncontrolled MPE limits
B	Advise your neighbors of the results of your tests
C	You need only evaluate exposure levels on your own property
D	Make sure signals from your station are less than the controlled MPE limits

Figure E9-3