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. - E1A08

If a station in a message forwarding system inadvertently forwards a message that is in violation of FCC rules, who is primarily accountable for the rules violation?

Select	Answer
A	The control operator of the originating station
B	The control operators of all the stations in the system
C	The control operators of all the stations in the system not authenticating the source from which they accept communications
D	The control operator of the packet bulletin board station

2. - E1B11

What is the permitted mean power of any spurious emission relative to the mean power of the fundamental emission from a station transmitter or external RF amplifier installed after January 1, 2003 and transmitting on a frequency below 30 MHZ?

Select	Answer
A	At least 63 dB below
B	At least 43 dB below
C	At least 53 dB below
D	At least 73 dB below

3. - E1C03

How do the control operator responsibilities of a station under automatic control differ from one under local control?

Select	Answer
A	Under automatic control the control operator is not required to be present at the control point
B	Under automatic control there is no control operator
C	Under local control there is no control operator
D	Under local control a control operator is not required 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 General, Advanced or Amateur Extra Class
B	All except Technician Class
C	Any class with appropriate operator privileges
D	Only Amateur Extra Class

5. - E1E07

What should a VE do if a candidate fails to comply with the examiner's instructions during an amateur operator license examination?

Select	Answer
A	Immediately terminate the candidate's examination
B	Immediately terminate everyone's examination and close the session
C	Warn the candidate that continued failure to comply will result in termination of the examination
D	Allow the candidate to complete the examination, but invalidate the results

6. - E1F06

Under what circumstances might the FCC issue a Special Temporary Authority (STA) to an amateur station?

Select	Answer
A	To provide additional spectrum for personal use
B	To allow regular operation on Land Mobile channels
C	To provide temporary operation while awaiting normal licensing
D	To provide for experimental amateur communications

7. - E2A09

What do the terms L band and S band specify with regard to satellite communications?

Select	Answer
A	The 23 centimeter and 13 centimeter bands
B	FM and Digital Store-and-Forward systems
C	Which sideband to use
D	The 2 meter and 70 centimeter bands

8. - E2B02

How many horizontal lines make up a fast-scan (NTSC) television frame?

Select	Answer
A	1080
B	525
C	30
D	60

9. - E2C02

Which of the following best describes the term self-spotting in regards to HF contest operating?

Select	Answer
A	The generally prohibited practice of posting one's own call sign and frequency on a spotting network
B	The acceptable practice of manually posting the call signs of stations on a spotting network
C	An automatic method for rapidly zero beating or tuning to a station's frequency before calling that station
D	A manual technique for rapidly zero beating or tuning to a station's frequency before calling that station

10. - E2D14

What is one advantage of using JT65 coding?

Select	Answer
A	Uses only a 65 Hz bandwidth
B	The ability to decode signals which have a very low signal to noise ratio
C	Permits fast-scan TV transmissions over narrow bandwidth
D	Easily copied by ear if necessary

11. - E2E04

What is indicated when one of the ellipses in an FSK crossed-ellipse display suddenly disappears?

Select	Answer
A	One of the signal filters is saturated
B	The mark and space signal have been inverted
C	The receiver has drifted 5 kHz from the desired receive frequency
D	Selective fading has occurred

12. - E3A16

Which of the following best describes electromagnetic waves traveling in free space?

Select	Answer
A	Changing electric and magnetic fields propagate the energy
B	The waves are reflected by the ionosphere and return to their source
C	The energy propagates through a medium with a high refractive index
D	Electric and magnetic fields become aligned as they travel

13. - E3B13

Why is chordal hop propagation desirable?

Select	Answer
A	The signal experiences less loss along the path compared to normal skip propagation
B	Signals travel faster along ionospheric chords
C	The MUF for chordal hop propagation is much lower than for normal skip propagation
D	Atmospheric noise is lower in the direction of chordal hop propagation

14. - E3C15

What might a sudden rise in radio background noise indicate?

Select	Answer
A	Long-path propagation is occurring
B	A solar flare has occurred
C	Increased transequatorial propagation likely
D	A meteor ping

15. - E4A13

How is the compensation of an oscilloscope probe typically adjusted?

Select	Answer
A	A frequency standard is displayed and the probe is adjusted until the deflection time is accurate
B	A square wave is displayed and the probe is adjusted until the horizontal portions of the displayed wave are as nearly flat as possible
C	A DC voltage standard is displayed and the probe is adjusted until the displayed voltage is accurate
D	A high frequency sine wave is displayed and the probe is adjusted for maximum amplitude

16. - E4B14

What happens if a dip meter is too tightly coupled to a tuned circuit being checked?

Select	Answer
A	Intermodulation distortion occurs
B	A less accurate reading results
C	Harmonics are generated
D	Cross modulation occurs

17. - E4C07

What does the MDS of a receiver represent?

Select	Answer
A	The maximum detectable spectrum
B	The minimum discernible signal
C	The multiplex distortion stability
D	The meter display sensitivity

18. - E4D06

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

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

19. - E4E12

What is one disadvantage of using some types of automatic DSP notch-filters when attempting to copy CW signals?

Select	Answer
A	Received CW signals will appear to be modulated at the DSP clock frequency
B	Ringing in the DSP filter will completely remove the spaces between the CW characters
C	Any nearby signal passing through the DSP system will overwhelm the desired signal
D	A DSP filter can remove the desired signal at the same time as it removes interfering signals

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	R/L
B	L/R
C	Minimum
D	Maximum

21. - E5B04

What is the time constant of a circuit having two 220 microfarad capacitors and two 1 megohm resistors, all in parallel?

Select	Answer
A	440 seconds
B	55 seconds
C	220 seconds
D	110 seconds

22. - E5C04

Which of the following represents a capacitive reactance in polar coordinates?

Select	Answer
A	A positive real part
B	A positive phase angle
C	A negative real part
D	A negative phase angle

23. - E5D09

What happens to reactive power in an AC circuit that has both ideal inductors and ideal capacitors?

Select	Answer
A	It is repeatedly exchanged between the associated magnetic and electric fields, but is not dissipated
B	It is dissipated in the formation of inductive and capacitive fields
C	It is dissipated as kinetic energy in the circuit
D	It is dissipated as heat in the circuit

24. - E6A11

In Figure E6-2, what is the schematic symbol for a P-channel junction FET?

Select	Answer
A	2
B	6
C	1
D	3

25. - E6B03

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

Select	Answer
A	Tunnel
B	Zener
C	Junction
D	Point contact

26. - E6C11

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

Select	Answer
A	2
B	6
C	4
D	5

27. - E6D08

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

Select	Answer
A	Powdered-iron cores generally maintain their characteristics at higher currents
B	Powdered-iron cores use smaller diameter wire for the same inductance
C	Powdered-iron cores generally require fewer turns to produce a given inductance
D	Powdered-iron cores generally have greater initial permeability

28. - E6E04

Which is the most common input and output impedance of circuits that use MMICs?

Select	Answer
A	50 ohms
B	300 ohms
C	450 ohms
D	10 ohms

29. - E6F07

What is a solid state relay?

Select	Answer
A	A relay using transistors to drive the relay coil
B	A passive delay line
C	A mechanical relay that latches in the on or off state each time it is pulsed
D	A device that uses semiconductors to implement the functions of an electromechanical relay

30. - E7A11

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

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

31. - E7B13

In Figure E7-2, what is the purpose of R?

Select	Answer
A	Voltage regulation
B	Collector load
C	Fixed bias
D	Emitter load

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. - E7D05

Which of the following types of linear voltage regulator places a constant load on the unregulated voltage source?

Select	Answer
A	A series regulator
B	A constant current source
C	A shunt current source
D	A shunt regulator

34. - E7E08

What are the principal frequencies that appear at the output of a mixer circuit?

Select	Answer
A	1.414 and 0.707 times the input frequency
B	The two input frequencies along with their sum and difference frequencies
C	The sum, difference and square root of the input frequencies
D	Two and four times the original frequency

35. - E7F11

What sets the minimum detectable signal level for an SDR in the absence of atmospheric or thermal noise?

Select	Answer
A	Sample clock phase noise
B	Data storage transfer rate
C	Missing codes and jitter
D	Reference voltage level and sample width in bits

36. - E7G04

What is meant by the term op-amp input offset voltage?

Select	Answer
A	The difference between the output voltage of the op-amp and the input voltage required in the immediately following stage
B	The output voltage of the op-amp minus its input voltage
C	The differential input voltage needed to bring the open loop output voltage to zero
D	The potential between the amplifier input terminals of the op-amp in an open loop condition

37. - E7H07

How can an oscillator's microphonic responses be reduced?

Select	Answer
A	Mechanically isolating the oscillator circuitry from its enclosure
B	Use of NP0 capacitors
C	Using the oscillator only for CW and digital signals
D	Eliminating noise on the oscillator's power supply

38. - E8A06

What is the approximate ratio of PEP-to-average power in a typical single-sideband phone signal?

Select	Answer
A	25 to 1
B	1 to 1
C	100 to 1
D	2.5 to 1

39. - E8B02

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

Select	Answer
A	It increases 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 decreases as the RF carrier frequency increases

40. - E8C11

What is the relationship between symbol rate and baud?

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

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 high power used by a spread spectrum transmitter keeps its signal from being easily overpowered
C	If interference is detected by the receiver it will signal the transmitter to change frequencies
D	The receiver is always equipped with a digital blanker

42. - E9A04

Which of the following factors may affect the feed point impedance of an antenna?

Select	Answer
A	Antenna height, conductor length/diameter ratio and location of nearby conductive objects
B	The settings of an antenna tuner at the transmitter
C	Transmission-line length
D	Sunspot activity and time of day

43. - E9B13

What does the abbreviation NEC stand for when applied to antenna modeling programs?

Select	Answer
A	Numeric Electrical Computation
B	National Electrical Code
C	Numerical Electromagnetic Code
D	Next Element Comparison

44. - E9C06

What is the effect of a terminating resistor on a rhombic antenna?

Select	Answer
A	It changes the radiation pattern from horizontal to vertical polarization
B	It reflects the standing waves on the antenna elements back to the transmitter
C	It changes the radiation pattern from bidirectional to unidirectional
D	It decreases the ground loss

45. - E9D02

How can linearly polarized Yagi antennas be used to produce circular polarization?

Select	Answer
A	Stack two Yagis fed 90 degrees out of phase to form an array with the respective elements in parallel planes
B	Arrange two Yagis perpendicular to each other with the driven elements at the same point on the boom fed 90 degrees out of phase
C	Arrange two Yagis collinear to each other with the driven elements fed 180 degrees out of phase
D	Stack two Yagis fed in phase to form an array with the respective elements in parallel planes

46. - E9E06

What is the equivalent lumped-constant network for a hairpin matching system of a 3-element Yagi?

Select	Answer
A	A shunt inductor
B	Pi-network
C	Pi-L-network
D	A series capacitor

47. - E9F05

What is the approximate physical length of a solid polyethylene dielectric coaxial transmission line that is electrically one-quarter wavelength long at 14.1 MHz?

Select	Answer
A	3.5 meters
B	2.3 meters
C	0.2 meters
D	20 meters

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	Reactance axis
B	Prime axis
C	Polar axis
D	Impedance axis

49. - E9H10

How can the output voltage of a multiple turn receiving loop antenna be increased?

Select	Answer
A	By winding adjacent turns in opposing directions
B	By increasing the number of wire turns in the loop and reducing the area of the loop structure
C	By reducing the permeability of the loop shield
D	By increasing either the number of wire turns in the loop or the area of the loop structure or both

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	Ingestion of ozone gas from the cooling system
D	Hearing loss caused by high voltage corona discharge

Figure E6-2

Figure E6-5

Figure E7-2

Figure E9-3