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

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1. - E1A07

Which amateur band requires transmission on specific channels rather than on a range of frequencies?

Select	Answer
A	17 meter band
B	60 meter band
C	30 meter band
D	12 meter band

2. - E1B05

What is the National Radio Quiet Zone?

Select	Answer
A	An area in Puerto Rico surrounding the Arecibo Radio Telescope
B	An area in Florida surrounding Cape Canaveral
C	An area surrounding the National Radio Astronomy Observatory
D	An area in New Mexico surrounding the White Sands Test Area

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	10.100 MHz - 10.150 MHz
D	24.940 MHz - 24.990 MHz

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

5. - E1E06

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

Select	Answer
A	Each administering VE
B	The VEC coordinating the session
C	The VE session manager
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 144 MHz
C	Only on amateur frequencies above 420 MHz
D	Only on amateur frequencies above 222 MHz

7. - E2A06

On what band would a satellite receive signals if it were operating in mode U/V?

Select	Answer
A	435 MHz - 438 MHz
B	144 MHz - 146 MHz
C	29.5 MHz - 29.7 MHz
D	50.0 MHz - 50.2 MHz

8. - E2B04

What is blanking in a video signal?

Select	Answer
A	Turning off the scanning beam at the conclusion of a transmission
B	Synchronization of the horizontal and vertical sync pulses
C	Transmitting a black and white test pattern
D	Turning off the scanning beam while it is traveling from right to left or from bottom to top

9. - E2C13

What indicator is required to be used by U.S.-licensed operators when operating a station via remote control where the transmitter is located in the U.S.?

Select	Answer
A	/ followed by the USPS two letter abbreviation for the state in which the remote station is located
B	/R# where # is the district of the remote station
C	No additional indicator is required
D	The ARRL section of the remote station

10. - E2D06

Which of the following describes a method of establishing EME contacts?

Select	Answer
A	Storing and forwarding digital messages
B	Judging optimum transmission times by monitoring beacons reflected from the Moon
C	High speed CW identification to avoid fading
D	Time synchronous transmissions alternately from each station

11. - E2E10

Which of these digital modes has the narrowest bandwidth?

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

12. - E3A11

What is a typical range for tropospheric propagation of microwave signals?

Select	Answer
A	10 miles to 50 miles
B	1200 miles
C	100 miles to 300 miles
D	2500 miles

13. - E3B07

Which of the following could account for hearing an echo on the received signal of a distant station?

Select	Answer
A	High D layer absorption
B	Transmit frequency is higher than the MUF
C	Meteor scatter
D	Receipt of a signal by more than one path

14. - E3C09

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

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

15. - E4A11

Which of the following is good practice when using an oscilloscope probe?

Select	Answer
A	All of these choices are correct
B	Never use a DC-coupled probe to measure an AC circuit
C	Keep the signal ground connection of the probe as short as possible
D	Never use a high impedance probe to measure a low impedance circuit

16. - E4B16

Which S parameter represents return loss or SWR?

Select	Answer
A	S12
B	S11
C	S21
D	S22

17. - E4C16

Which of the following is caused by missing codes in an SDR receiver's analog-to-digital converter?

Select	Answer
A	Excess output level
B	Overload
C	Loss of sensitivity
D	Distortion

18. - E4D07

Which describes the most significant effect of an off-frequency signal when it is causing cross-modulation interference to a desired signal?

Select	Answer
A	The off-frequency unwanted signal is heard in addition to the desired signal
B	A large increase in background noise
C	The desired signal can no longer be heard
D	A reduction in apparent signal strength

19. - E4E02

Which of the following types of receiver noise can often be reduced with a DSP noise filter?

Select	Answer
A	Power line noise
B	Ignition noise
C	Broadband white noise
D	All of these choices are correct

20. - E5A17

What is the result of increasing the Q of an impedance-matching circuit?

Select	Answer
A	Matching range is increased
B	It has no effect on impedance matching
C	Matching bandwidth is increased
D	Matching bandwidth is decreased

21. - E5B06

What is susceptance?

Select	Answer
A	The magnetic impedance of a circuit
B	A measure of the efficiency of a transformer
C	The ratio of magnetic field to electric field
D	The inverse of reactance

22. - E5C14

Which point on Figure E5-2 best represents the impedance of a series circuit consisting of a 400 ohm resistor and a 38 picofarad capacitor at 14 MHz?

Select	Answer
A	Point 4
B	Point 6
C	Point 2
D	Point 5

23. - E5D15

What is the power factor of an R-L circuit having a 45 degree phase angle between the voltage and the current?

Select	Answer
A	0.707
B	0.866
C	0.5
D	1.0

24. - E6A07

Which of the following indicates that a silicon NPN junction transistor is biased on?

Select	Answer
A	Base-to-emitter voltage of approximately 0.6 to 0.7 volts
B	Base-to-emitter voltage of approximately 6 to 7 volts
C	Base-to-emitter resistance of approximately 6 to 7 ohms
D	Base-to-emitter resistance of approximately 0.6 to 0.7 ohms

25. - E6B09

What is a common use for point contact diodes?

Select	Answer
A	As an RF detector
B	As a high voltage rectifier
C	As a constant current source
D	As a constant voltage source

26. - E6C07

What best describes a pull-up or pull-down resistor?

Select	Answer
A	A resistor connected to an op-amp output that only functions when the logic output is false
B	A resistor connected to the positive or negative supply line used to establish a voltage when an input or output is an open circuit
C	A resistor in a keying circuit used to reduce key clicks
D	A resistor that insures that an oscillator frequency does not drive lower over time

27. - E6D17

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

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

28. - E6E07

Which of the following is typically used to construct a MMIC-based microwave amplifier?

Select	Answer
A	Ground-plane construction
B	Microstrip construction
C	Point-to-point construction
D	Wave-soldering construction

29. - E6F10

What is the most common type of photovoltaic cell used for electrical power generation?

Select	Answer
A	Selenium
B	Cadmium Sulfide
C	Silicon
D	Copper oxide

30. - E7A03

Which of the following can divide the frequency of a pulse train by 2?

Select	Answer
A	An XOR gate
B	An OR gate
C	A multiplexer
D	A flip-flop

31. - E7B06

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

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

32. - E7C13

What is one advantage of a Pi-matching network over an L-matching network consisting of a single inductor and a single capacitor?

Select	Answer
A	Pi-networks are designed for balanced input and output
B	L-networks cannot perform impedance transformation
C	Pi-networks have fewer components
D	The Q of Pi-networks can be varied depending on the component values chosen

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

34. - E7E03

How does an analog phase modulator function?

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

35. - E7F12

What digital process is applied to I and Q signals in order to recover the baseband modulation information?

Select	Answer
A	Quadrature mixing
B	Decimation
C	Signal conditioning
D	Fast Fourier Transform

36. - E7G05

How can unwanted ringing and audio instability be prevented in a multi-section op-amp RC audio filter circuit?

Select	Answer
A	Restrict both gain and Q
B	Restrict Q but increase gain
C	Increase both gain and Q
D	Restrict gain but increase Q

37. - E7H12

Which of the following must be done to insure that a crystal oscillator provides the frequency specified by the crystal manufacturer?

Select	Answer
A	Bias the crystal at a specified current
B	Provide the crystal with a specified parallel capacitance
C	Bias the crystal at a specified voltage
D	Provide the crystal with a specified parallel inductance

38. - E8A10

What is the purpose of a low pass filter used in conjunction with a digital-to-analog converter?

Select	Answer
A	Improve accuracy by removing out of sequence codes from the input
B	Lower the input bandwidth to increase the effective resolution
C	All of these choices are correct
D	Remove harmonics from the output caused by the discrete analog levels generated

39. - E8B03

What is the modulation index of an FM-phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency when the modulating frequency is 1000 Hz?

Select	Answer
A	1000
B	3000
C	3
D	0.3

40. - E8C04

What technique is used to minimize the bandwidth requirements of a PSK31 signal?

Select	Answer
A	Reed-Solomon character encoding
B	Zero-sum character encoding
C	Use of trapezoidal data pulses
D	Use of sinusoidal data pulses

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 is possible to transmit both upper and lower case text
D	It uses one character as a shift code to send numeric and special characters

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	Isolate the coax shield from ground
C	Shorten the radiating element
D	Install a good radial system

43. - E9B05

What type of antenna pattern over real ground is shown in Figure E9-2?

Select	Answer
A	Radiation resistance
B	Polarization
C	Elevation
D	Azimuth

44. - E9C09

What is a G5RV antenna?

Select	Answer
A	A phased array antenna consisting of multiple loops
B	A multi-band dipole antenna fed with coax and a balun through a selected length of open wire transmission line
C	A wide band dipole using shorted coaxial cable for the radiating elements and fed with a 4:1 balun
D	A multi-band trap antenna

45. - E9D13

What usually occurs if a Yagi antenna is designed solely for maximum forward gain?

Select	Answer
A	The SWR is reduced
B	The frequency response is widened over the whole frequency band
C	The front-to-back ratio increases
D	The front-to-back ratio decreases

46. - E9E01

What system matches a higher impedance transmission line to a lower impedance antenna by connecting the line to the driven element in two places spaced a fraction of a wavelength each side of element center?

Select	Answer
A	The delta matching system
B	The omega matching system
C	The gamma matching system
D	The stub matching system

47. - E9F09

What is the approximate physical length of a solid polyethylene dielectric coaxial transmission line that is electrically one-quarter wavelength long at 7.2 MHz?

Select	Answer
A	24 meters
B	10 meters
C	50 meters
D	6.9 meters

48. - E9G10

What do the arcs on a Smith chart represent?

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

49. - E9H11

What characteristic of a cardioid pattern antenna is useful for direction finding?

Select	Answer
A	High-radiation angle
B	A very sharp single null
C	A very sharp peak
D	Broad band response

50. - E0A11

Which of the following injuries can result from using high-power UHF or microwave transmitters?

Select	Answer
A	Blood clotting from the intense magnetic field
B	Localized heating of the body from RF exposure in excess of the MPE limits
C	Hearing loss caused by high voltage corona discharge
D	Ingestion of ozone gas from the cooling system

Figure E5-2

Figure E9-2