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

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1. - E1A13

Who must be in physical control of the station apparatus of an amateur station aboard any vessel or craft that is documented or registered in the United States?

Select	Answer
A	Only a person named in an amateur station license grant
B	Any person named in an amateur station license grant or a person holding an unrestricted Radiotelephone Operator Permit
C	Only a person with an FCC Marine Radio
D	Any person holding an FCC issued amateur license or who is authorized for alien reciprocal operation

2. - E1B01

Which of the following constitutes a spurious emission?

Select	Answer
A	An emission outside its necessary bandwidth that can be reduced or eliminated without affecting the information transmitted
B	An amateur station transmission made at random without the proper call sign identification
C	Any transmitted signal that unintentionally interferes with another licensed radio station
D	A signal transmitted to prevent its detection by any station other than the intended recipient

3. - E1C06

Which of the following statements concerning remotely controlled amateur stations is true?

Select	Answer
A	Repeater and auxiliary stations may not be remotely controlled
B	A control operator must be present at the control point
C	Only Extra Class operators may be the control operator of a remote station
D	A control operator need not be present at the control point

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

5. - E1E01

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

Select	Answer
A	4
B	2
C	3
D	5

6. - E1F10

What is the maximum permitted transmitter peak envelope power for an amateur station transmitting spread spectrum communications?

Select	Answer
A	10 W
B	1.5 W
C	1 W
D	1.5 kW

7. - E2A02

What is the direction of a descending pass for an amateur satellite?

Select	Answer
A	From east to west
B	From north to south
C	From south to north
D	From west to east

8. - E2B14

What aspect of an amateur slow-scan television signal encodes the brightness of the picture?

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

10. - E2D02

Which of the following is a good technique for making meteor scatter contacts?

Select	Answer
A	15 second timed transmission sequences with stations alternating based on location
B	All of these choices are correct
C	Short transmission with rapidly repeated call signs and signal reports
D	Use of high speed CW or digital modes

11. - E2E03

How is the timing of JT65 contacts organized?

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

12. - E3A11

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

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

13. - E3B12

What is the primary characteristic of chordal hop propagation?

Select	Answer
A	Successive ionospheric reflections without an intermediate reflection from the ground
B	Signals reflected back toward the transmitting station
C	Propagation away from the great circle bearing between stations
D	Propagation across the geomagnetic equator

14. - E3C01

What does the term ray tracing describe in regard to radio communications?

Select	Answer
A	Determining the radiation pattern from an array of antennas
B	Modeling a radio wave's path through the ionosphere
C	Evaluating high voltage sources for X-Rays
D	The process in which an electronic display presents a pattern

15. - E4A14

What is the purpose of the prescaler function on a frequency counter?

Select	Answer
A	It multiplies a higher frequency signal so a low-frequency counter can display the operating frequency
B	It amplifies low level signals for more accurate counting
C	It prevents oscillation in a low-frequency counter circuit
D	It divides a higher frequency signal so a low-frequency counter can display the input frequency

16. - E4B01

Which of the following factors most affects the accuracy of a frequency counter?

Select	Answer
A	Time base accuracy
B	Temperature coefficient of the logic
C	Input attenuator accuracy
D	Decade divider accuracy

17. - E4C09

Which of the following choices is a good reason for selecting a high frequency for the design of the IF in a conventional HF or VHF communications receiver?

Select	Answer
A	Reduced drift
B	Fewer components in the receiver
C	Improved receiver noise figure
D	Easier for front-end circuitry to eliminate image responses

18. - E4D12

What is the term for the reduction in receiver sensitivity caused by a strong signal near the received frequency?

Select	Answer
A	Quieting
B	Desensitization
C	Cross-modulation interference
D	Squelch gain rollback

19. - E4E04

How can conducted and radiated noise caused by an automobile alternator be suppressed?

Select	Answer
A	By connecting the radio's power leads directly to the battery and by installing coaxial capacitors in line with the alternator leads
B	By installing filter capacitors in series with the DC power lead and a blocking capacitor in the field lead
C	By installing a noise suppression resistor and a blocking capacitor in both leads
D	By installing a high-pass filter in series with the radio's power lead and a low-pass filter in parallel with the field lead

20. - E5A12

What is the half-power bandwidth of a parallel resonant circuit that has a resonant frequency of 3.7 MHz and a Q of 118?

Select	Answer
A	31.4 kHz
B	436.6 kHz
C	218.3 kHz
D	15.7 kHz

21. - E5B06

What is susceptance?

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

22. - E5C02

How are impedances described in polar coordinates?

Select	Answer
A	By real and imaginary parts
B	By Y and G values
C	By phase angle and amplitude
D	By X and R values

23. - E5D01

What is the result of skin effect?

Select	Answer
A	As frequency decreases, RF current flows in a thinner layer of the conductor, closer to the surface
B	Thermal effects on the surface of the conductor decrease the impedance
C	Thermal effects on the surface of the conductor increase the impedance
D	As frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface

24. - E6A12

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

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

25. - E6B11

What is used to control the attenuation of RF signals by a PIN diode?

Select	Answer
A	Forward DC bias current
B	Capacitance of an RF coupling capacitor
C	Reverse voltage larger than the RF signal
D	A sub-harmonic pump signal

26. - E6C08

In Figure E6-5, what is the schematic symbol for a NAND gate?

Select	Answer
A	3
B	1
C	2
D	4

27. - E6D05

What is one reason for using ferrite cores rather than powdered-iron in an inductor?

Select	Answer
A	Ferrite toroids generally have lower initial permeability
B	Ferrite toroids are easier to use with surface mount technology
C	Ferrite toroids generally require fewer turns to produce a given inductance value
D	Ferrite toroids generally have better temperature stability

28. - E6E10

What is the packaging technique in which leadless components are soldered directly to circuit boards?

Select	Answer
A	Virtual lead mounting
B	Surface mount
C	Stripped lead
D	Direct soldering

29. - E6F08

Why are optoisolators often used in conjunction with solid state circuits when switching 120VAC?

Select	Answer
A	Optoisolators provide impedance matching between the control circuit and power circuit
B	Optoisolators provide a low impedance link between a control circuit and a power circuit
C	Optoisolators eliminate the effects of reflected light in the control circuit
D	Optoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched

30. - E7A10

What is a truth table?

Select	Answer
A	A table of logic symbols that indicate the high logic states of an op-amp
B	A diagram showing logic states when the digital device output is true
C	A table of logic symbols that indicate the logic states of an op-amp
D	A list of inputs and corresponding outputs for a digital device

31. - E7B11

In Figure E7-1, what is the purpose of R3?

Select	Answer
A	Fixed bias
B	Self bias
C	Emitter bypass
D	Output load resistor

32. - E7C15

What is a crystal lattice filter?

Select	Answer
A	An audio filter made with four quartz crystals that resonate at 1kHz intervals
B	A filter with wide bandwidth and shallow skirts made using quartz crystals
C	A power supply filter made with interlaced quartz crystals
D	A filter with narrow bandwidth and steep skirts made using quartz crystals

33. - E7D03

What device is typically used as a stable reference voltage in a linear voltage regulator?

Select	Answer
A	A varactor diode
B	A Zener diode
C	A tunnel diode
D	An SCR

34. - E7E02

What is the function of a reactance modulator?

Select	Answer
A	To produce PM signals by using an electrically variable resistance
B	To produce AM signals by using an electrically variable inductance or capacitance
C	To produce AM signals by using an electrically variable resistance
D	To produce PM signals by using an electrically variable inductance or capacitance

35. - E7F04

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

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

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 gain but increase Q
C	Restrict Q but increase gain
D	Increase both gain and Q

37. - E7H02

Which describes a microphonic?

Select	Answer
A	An IC used for amplifying microphone signals
B	Excess loading of the microphone by an oscillator
C	Changes in oscillator frequency due to mechanical vibration
D	Distortion caused by RF pickup on the microphone cable

38. - E8A01

What is the name of the process that shows that a square wave is made up of a sine wave plus all of its odd harmonics?

Select	Answer
A	Fourier analysis
B	Numerical analysis
C	Differential analysis
D	Vector analysis

39. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

Select	Answer
A	A frequency modulation technique which uses non-harmonically related frequencies
B	A digital mode for narrow band, slow speed transmissions
C	A digital modulation technique using subcarriers at frequencies chosen to avoid intersymbol interference
D	A bandwidth compression technique using Fourier transforms

40. - E8C11

What is the relationship between symbol rate and baud?

Select	Answer
A	They are the same
B	Baud is only used for RTTY
C	Symbol rate is only used for packet-based modes
D	Baud is twice the symbol rate

41. - E8D12

What is the advantage of including a parity bit with an ASCII character stream?

Select	Answer
A	Some types of errors can be detected SUBELEMENT E9 - ANTENNAS AND TRANSMISSION LINES [8 Exam Questions - 8 Groups] E9A Basic Antenna parameters: radiation resistance, gain, beamwidth, efficiency, beamwidth; effective radiated power, polarization E9A01 (C) What describes an isotropic antenna? A. A grounded antenna used to measure earth conductivity B. A horizontally polarized antenna used to compare Yagi antennas C. A theoretical antenna used as a reference for antenna gain D. A spacecraft antenna used to direct signals toward the earth
B	The signal can overpower interfering signals
C	Foreign language characters can be sent
D	Faster transmission rate

42. - E9A14

What is meant by the radiation resistance of an antenna?

Select	Answer
A	The resistance in the atmosphere that an antenna must overcome to be able to radiate a signal
B	The combined losses of the antenna elements and feed line
C	The value of a resistance that would dissipate the same amount of power as that radiated from an antenna
D	The specific impedance of the antenna

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	The antenna will become mechanically unstable
C	Ground conductivity will not be accurately modeled
D	The resulting design will favor radiation of harmonic energy

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 main lobe takeoff angle increases with increasing height
C	The horizontal beam width increases with height
D	The horizontal beam width decreases with height

45. - E9D10

What happens to feed point impedance at the base of a fixed length HF mobile antenna as the frequency of operation is lowered?

Select	Answer
A	The radiation resistance decreases and the capacitive reactance decreases
B	The radiation resistance increases and the capacitive reactance decreases
C	The radiation resistance decreases and the capacitive reactance increases
D	The radiation resistance increases and the capacitive reactance increases

46. - E9E09

Which of these matching systems is an effective method of connecting a 50 ohm coaxial cable feed line to a grounded tower so it can be used as a vertical antenna?

Select	Answer
A	Gamma match
B	All of these choices are correct
C	Hairpin match
D	Double-bazooka match

47. - E9F01

What is the velocity factor of a transmission line?

Select	Answer
A	The velocity of the wave in the transmission line multiplied by the velocity of light in a vacuum
B	The ratio of the characteristic impedance of the line to the terminating impedance
C	The index of shielding for coaxial cable
D	The velocity of the wave in the transmission line divided by the velocity of light in a vacuum

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 current axis
C	The voltage axis
D	The resistance axis

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

50. - E0A07

How may dangerous levels of carbon monoxide from an emergency generator be detected?

Select	Answer
A	By the odor
B	By the yellowish appearance of the gas
C	Any ordinary smoke detector can be used
D	Only with a carbon monoxide detector

Figure E6-5

Figure E7-1

Figure E9-3