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

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1. - E1A10

If an amateur station is installed aboard a ship or aircraft, what condition must be met before the station is operated?

Select	Answer
A	Its operation must be approved by the master of the ship or the pilot in command of the aircraft
B	The amateur station operator must agree not to transmit when the main radio of the ship or aircraft is in use
C	The amateur operator must have an FCC Marine or Aircraft endorsement on his or her amateur license
D	The amateur station must have a power supply that is completely independent of the main ship or aircraft power supply

2. - E1B02

Which of the following factors might cause the physical location of an amateur station apparatus or antenna structure to be restricted?

Select	Answer
A	The location is of environmental importance or significant in American history, architecture, or culture
B	The location is of geographical or horticultural importance
C	The location is near an area of political conflict
D	The location is in an ITU Zone designated for coordination with one or more foreign governments

3. - E1C12

What types of communications may be transmitted to amateur stations in foreign countries?

Select	Answer
A	Business-related messages for non-profit organizations
B	Communications incidental to the purpose of the amateur service and remarks of a personal nature
C	Messages intended for connection to users of the maritime satellite service
D	All of these choices are correct

4. - E1D04

What is an Earth station in the amateur satellite service?

Select	Answer
A	An amateur station that is not able to communicate using amateur satellites
B	An amateur station that transmits telemetry consisting of measurement of upper atmosphere
C	An amateur station within 50 km of the Earth's surface intended for communications with amateur stations by means of objects in space
D	Any amateur station on the surface of the Earth

5. - E1E05

What is the minimum passing score on amateur operator license examinations?

Select	Answer
A	Minimum passing score of 74%
B	Minimum passing score of 80%
C	Minimum passing score of 70%
D	Minimum passing score of 77%

6. - E1F04

Which of the following geographic descriptions approximately describes "Line A"?

Select	Answer
A	A line roughly parallel to and east of the U.S. Pacific coastline
B	A line roughly parallel to and west of the U.S. Atlantic coastline
C	A line roughly parallel to and north of the U.S.-Mexican border and Gulf coastline
D	A line roughly parallel to and south of the U.S.-Canadian border

7. - E2A06

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

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

8. - E2B05

Which of the following is an advantage of using vestigial sideband for standard fast- scan TV transmissions?

Select	Answer
A	The vestigial sideband carries the audio information
B	The vestigial sideband contains chroma information
C	Vestigial sideband reduces bandwidth while allowing for simple video detector circuitry
D	Vestigial sideband provides high frequency emphasis to sharpen the picture

9. - E2C08

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

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

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

11. - E2E08

Which of the following HF digital modes can be used to transfer binary files?

Select	Answer
A	RTTY
B	AMTOR
C	PACTOR
D	Hellschreiber

12. - E3A12

What is the cause of auroral activity?

Select	Answer
A	A low sunspot level combined with tropospheric ducting
B	Meteor showers concentrated in the extreme northern and southern latitudes
C	The interaction in the E layer of charged particles from the Sun with the Earth's magnetic field
D	The interaction in the F2 layer between the solar wind and the Van Allen belt

13. - E3B14

What happens to linearly polarized radio waves that split into ordinary and extraordinary waves in the ionosphere?

Select	Answer
A	They are bent toward the magnetic poles
B	They become phase-locked
C	They become elliptically polarized
D	Their polarization is randomly modified

14. - E3C08

What does the space weather term G5 mean?

Select	Answer
A	Moderate solar wind
B	Waning sunspot numbers
C	An extreme geomagnetic storm
D	Very low solar activity

15. - E4A10

Which of the following displays multiple digital signal states simultaneously?

Select	Answer
A	Logic analyzer
B	Bit error rate tester
C	Network analyzer
D	Modulation monitor

16. - E4B08

Which of the following is a characteristic of a good DC voltmeter?

Select	Answer
A	Low reluctance input
B	Low impedance input
C	High impedance input
D	High reluctance input

17. - E4C12

What is an undesirable effect of using too wide a filter bandwidth in the IF section of a receiver?

Select	Answer
A	Filter ringing
B	Undesired signals may be heard
C	Output-offset overshoot
D	Thermal-noise distortion

18. - E4D13

Which of the following can cause receiver desensitization?

Select	Answer
A	Strong adjacent channel signals
B	Audio bias adjusted too high
C	Audio gain adjusted too low
D	Squelch gain misadjusted

19. - E4E03

Which of the following signals might a receiver noise blanker be able to remove from desired signals?

Select	Answer
A	Signals which have a sharply peaked frequency distribution
B	Signals which appear at one IF but not another
C	Signals which appear across a wide bandwidth
D	Signals which are constant at all IF levels

20. - E5A13

What is an effect of increasing Q in a resonant circuit?

Select	Answer
A	Phase shift can become uncontrolled
B	Internal voltages and circulating currents increase
C	Fewer components are needed for the same performance
D	Parasitic effects are minimized

21. - E5B02

What is the term for the time it takes for a charged capacitor in an RC circuit to discharge to 36.8% of its initial voltage?

Select	Answer
A	One discharge period
B	A discharge factor of one
C	One time constant
D	An exponential discharge rate of one

22. - E5C07

What is a vector?

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

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	0.5
B	0.707
C	1.0
D	0.866

24. - E6A10

In Figure E6-2, what is the schematic symbol for an N-channel dual-gate MOSFET?

Select	Answer
A	6
B	4
C	2
D	5

25. - E6B09

What is a common use for point contact diodes?

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

26. - E6C01

What is the function of hysteresis in a comparator?

Select	Answer
A	To increase the sensitivity
B	To cause the output to change states continually
C	To allow the comparator to be used with AC input signal
D	To prevent input noise from causing unstable output signals

27. - E6D07

What is the usable frequency range of inductors that use toroidal cores, assuming a correct selection of core material for the frequency being used?

Select	Answer
A	From about 100 kHz to at least 1000 GHz
B	From approximately 10 Hz to no more than 3000 kHz
C	From a few kHz to no more than 30 MHz
D	From less than 20 Hz to approximately 300 MHz

28. - E6E05

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

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

29. - E6F09

What is the efficiency of a photovoltaic cell?

Select	Answer
A	The output RF power divided by the input DC power
B	The effective payback period
C	The relative fraction of light that is converted to current
D	The open-circuit voltage divided by the short-circuit current under full illumination

30. - E7A05

Which of the following is a circuit that continuously alternates between two states without an external clock?

Select	Answer
A	T flip-flop
B	Monostable multivibrator
C	J-K flip-flop
D	Astable multivibrator

31. - E7B09

Which of the following describes how the loading and tuning capacitors are to be adjusted when tuning a vacuum tube RF power amplifier that employs a Pi-network output circuit?

Select	Answer
A	The tuning capacitor is set to maximum capacitance and the loading capacitor is adjusted for minimum plate permissible current
B	The loading capacitor is set to maximum capacitance and the tuning capacitor is adjusted for minimum allowable plate current
C	The tuning capacitor is adjusted for minimum plate current, and the loading capacitor is adjusted for maximum permissible plate current
D	The loading capacitor is adjusted to minimum plate current while alternately adjusting the tuning capacitor for maximum allowable plate current

32. - E7C05

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

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

33. - E7D15

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

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

34. - E7E11

Which type of detector is used for demodulating SSB signals?

Select	Answer
A	Product detector
B	Phase comparator
C	Phase detector
D	Discriminator

35. - E7F15

Which of the following is an advantage of a Finite Impulse Response (FIR) filter vs an Infinite Impulse Response (IIR) digital filter?

Select	Answer
A	FIR filters are easier to implement for a given set of passband rolloff requirements
B	FIR filters can respond faster to impulses
C	All of these choices are correct
D	FIR filters delay all frequency components of the signal by the same amount

36. - E7G02

What is the effect of ringing in a filter?

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

37. - E7H03

How is positive feedback supplied in a Hartley oscillator?

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

38. - E8A12

What is an advantage of using digital signals instead of analog signals to convey the same information?

Select	Answer
A	Digital signals always occupy a narrower bandwidth
B	Less complex circuitry is required for digital signal generation and detection
C	All of these choices are correct
D	Digital signals can be regenerated multiple times without error

39. - E8B06

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz when the maximum modulation frequency is 3.5 kHz?

Select	Answer
A	2.14
B	0.47
C	0.214
D	47

40. - E8C01

How is Forward Error Correction implemented?

Select	Answer
A	By transmitting a special algorithm to the receiving station along with the data characters
B	By the receiving station repeating each block of three data characters
C	By transmitting extra data that may be used to detect and correct transmission errors
D	By varying the frequency shift of the transmitted signal according to a predefined algorithm

41. - E8D03

How does the spread spectrum technique of frequency hopping work?

Select	Answer
A	If interference is detected by the receiver it will signal the transmitter to change frequencies
B	If interference is detected by the receiver it will signal the transmitter to wait until the frequency is clear
C	A pseudo-random binary bit stream is used to shift the phase of an RF carrier very rapidly in a particular sequence
D	The frequency of the transmitted signal is changed very rapidly according to a particular sequence also used by the receiving station

42. - E9A03

Why would one need to know the feed point impedance of an antenna?

Select	Answer
A	To measure the near-field radiation density from a transmitting antenna
B	To match impedances in order to minimize standing wave ratio on the transmission line
C	To calculate the front-to-back ratio of the antenna
D	To calculate the front-to-side ratio of the antenna

43. - E9B05

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

Select	Answer
A	Polarization
B	Radiation resistance
C	Elevation
D	Azimuth

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	No change occurs
B	It is increased
C	It is decreased
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 stub match
C	The delta match
D	The epsilon match

47. - E9F10

What impedance does a 1/8 wavelength transmission line present to a generator when the line is shorted at the far end?

Select	Answer
A	A capacitive reactance
B	The same as the characteristic impedance of the line
C	The same as the input impedance to the final generator stage
D	An inductive reactance

48. - E9G04

What are the two families of circles and arcs that make up a Smith chart?

Select	Answer
A	Voltage and impedance
B	Resistance and reactance
C	Reactance and voltage
D	Resistance and voltage

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 compensates for the effects of an isotropic antenna, thereby improving directivity
C	It narrows the bandwidth of the received signal to improve signal to noise ratio
D	It reduces loss of received signals caused by antenna pattern nulls, thereby increasing sensitivity

50. - E0A01

What is the primary function of an external earth connection or ground rod?

Select	Answer
A	Reduce RFI to telephones and home entertainment systems
B	Lightning protection
C	Reduce received noise
D	Reduce RF current flow between pieces of equipment

Figure E6-2

Figure E9-2