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 operators of all the stations in the system
B	The control operator of the packet bulletin board station
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 originating station

2. - E1B09

Which amateur stations may be operated under RACES rules?

Select	Answer
A	Only those club stations licensed to Amateur Extra class operators
B	Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served
C	Any FCC-licensed amateur station except a Technician class
D	Any FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)

3. - E1C04

What is meant by IARP?

Select	Answer
A	A forecast of intermittent aurora radio propagation
B	The internal amateur radio practices policy of the FCC
C	An international amateur radio permit that allows U.S. amateurs to operate in certain countries of the Americas
D	An indication of increased antenna reflected power

4. - E1D03

What is a telecommand station in the amateur satellite service?

Select	Answer
A	An amateur station that transmits communications to initiate, modify or terminate functions of a space station
B	An amateur station that transmits telemetry consisting of measurements of upper atmosphere
C	An amateur station located on the Earth's surface for communication with other Earth stations by means of Earth satellites
D	An amateur station located more than 50 km above the Earth's surface

5. - E1E04

Which of the following best describes the Volunteer Examiner accreditation process?

Select	Answer
A	The prospective VE obtains accreditation from the FCC
B	Each General, Advanced and Amateur Extra Class operator is automatically accredited as a VE when the license is granted
C	The procedure by which a VEC confirms that the VE applicant meets FCC requirements to serve as an examiner
D	The amateur operator applying must pass a VE examination administered by the FCC Enforcement Bureau

6. - E1F03

Under what circumstances may a dealer sell an external RF power amplifier capable of operation below 144 MHz if it has not been granted FCC certification?

Select	Answer
A	It was imported from a manufacturer in a country that does not require certification of RF power amplifiers
B	The equipment dealer assembled it from a kit
C	It was purchased in used condition from an amateur operator and is sold to another amateur operator for use at that operator's station
D	It was imported from a manufacturer in another country and was certificated by that country's government

7. - E2A13

What type of satellite appears to stay in one position in the sky?

Select	Answer
A	LEO
B	Geostationary
C	HEO
D	Geomagnetic

8. - E2B09

What hardware, other than a receiver with SSB capability and a suitable computer, is needed to decode SSTV using Digital Radio Mondiale (DRM)?

Select	Answer
A	A special front end limiter
B	A special IF converter
C	A special notch filter to remove synchronization pulses
D	No other hardware is needed

9. - E2C10

Why might a DX station state that they are listening on another frequency?

Select	Answer
A	To separate the calling stations from the DX station
B	To improve operating efficiency by reducing interference
C	All of these choices are correct
D	Because the DX station may be transmitting on a frequency that is prohibited to some responding stations

10. - E2D01

Which of the following digital modes is especially designed for use for meteor scatter signals?

Select	Answer
A	FSK441
B	APRS
C	WSPR
D	Hellschreiber

11. - E2E13

Which of the following is a possible reason that attempts to initiate contact with a digital station on a clear frequency are unsuccessful?

Select	Answer
A	All of these choices are correct
B	The protocol version you are using is not the supported by the digital station
C	Your transmit frequency is incorrect
D	Another station you are unable to hear is using the frequency

12. - E3A10

Which type of atmospheric structure can create a path for microwave propagation?

Select	Answer
A	The jet stream
B	Temperature inversion
C	Wind shear
D	Dust devil

13. - E3B10

What is the cause of gray-line propagation?

Select	Answer
A	At mid-afternoon, the Sun heats the ionosphere decreasing radio wave refraction and the MUF
B	In darkness, solar absorption drops greatly while atmospheric ionization remains steady
C	At twilight and sunrise, D-layer absorption is low while E-layer and F-layer propagation remains high
D	At midday, the Sun super heats the ionosphere causing increased refraction of radio waves

14. - E3C09

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

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

15. - E4A01

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

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

16. - E4B05

If a frequency counter with a specified accuracy of +/- 10 ppm reads 146,520,000 Hz, what is the most the actual frequency being measured could differ from the reading?

Select	Answer
A	146.52 Hz
B	1465.20 Hz
C	146.52 kHz
D	10 Hz

17. - E4C13

How does a narrow-band roofing filter affect receiver performance?

Select	Answer
A	All of these choices are correct
B	It improves sensitivity by reducing front end noise
C	It improves dynamic range by attenuating strong signals near the receive frequency
D	It improves intelligibility by using low Q circuitry to reduce ringing

18. - E4D01

What is meant by the blocking dynamic range of a receiver?

Select	Answer
A	The difference in dB between the noise floor and the third order intercept point
B	The minimum difference in dB between the levels of two FM signals which will cause one signal to block the other
C	The minimum difference in dB between two signals which produce third order intermodulation products greater than the noise floor
D	The difference in dB between the noise floor and the level of an incoming signal which will cause 1 dB of gain compression

19. - E4E15

Which of the following can cause shielded cables to radiate or receive interference?

Select	Answer
A	Use of braided shielding material
B	Low inductance ground connections at both ends of the shield
C	Tying all ground connections to a common point resulting in differential mode currents in the shield
D	Common mode currents on the shield and conductors

20. - E5A14

What is the resonant frequency of a series RLC circuit if R is 22 ohms, L is 50 microhenrys and C is 40 picofarads?

Select	Answer
A	1.78 MHz
B	44.72 MHz
C	22.36 MHz
D	3.56 MHz

21. - E5B07

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 500 ohms, R is 1 kilohm, and XL is 250 ohms?

Select	Answer
A	68.2 degrees with the voltage lagging the current
B	14.0 degrees with the voltage lagging the current
C	14.0 degrees with the voltage leading the current
D	68.2 degrees with the voltage leading the current

22. - E5C10

When using rectangular coordinates to graph the impedance of a circuit, what does the vertical axis represent?

Select	Answer
A	Resistive component
B	The sum of the reactive and resistive components
C	Reactive component
D	The difference between the resistive and reactive components

23. - E5D12

How many watts are consumed in a circuit having a power factor of 0.2 if the input is 100-VAC at 4 amperes?

Select	Answer
A	80 watts
B	400 watts
C	2000 watts
D	50 watts

24. - E6A10

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

Select	Answer
A	4
B	2
C	5
D	6

25. - E6B03

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

Select	Answer
A	Point contact
B	Tunnel
C	Junction
D	Zener

26. - E6C01

What is the function of hysteresis in a comparator?

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

27. - E6D05

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

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

28. - E6E03

Which of the following materials is likely to provide the highest frequency of operation when used in MMICs?

Select	Answer
A	Silicon
B	Gallium nitride
C	Silicon nitride
D	Silicon dioxide

29. - E6F13

What is a liquid crystal display (LCD)?

Select	Answer
A	A frequency-determining unit for a transmitter or receiver
B	A display utilizing a crystalline liquid and polarizing filters which becomes opaque when voltage is applied
C	A display that uses a glowing liquid to remain brightly lit in dim light
D	A modern replacement for a quartz crystal oscillator which displays its fundamental frequency

30. - E7A03

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

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

31. - E7B08

How can an RF power amplifier be neutralized?

Select	Answer
A	By feeding a 180-degree out-of-phase portion of the output back to the input
B	By feeding an in-phase component of the output back to the input
C	By increasing the driving power
D	By reducing the driving power

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 passive op-amp filter
C	A Butterworth filter
D	A Chebyshev filter

33. - E7D16

When several electrolytic filter capacitors are connected in series to increase the operating voltage of a power supply filter circuit, why should resistors be connected across each capacitor?

Select	Answer
A	To equalize, as much as possible, the voltage drop across each capacitor
B	All of these choices are correct
C	To provide a minimum load current to reduce voltage excursions at light loads
D	To provide a safety bleeder to discharge the capacitors when the supply is off

34. - E7E11

Which type of detector is used for demodulating SSB signals?

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

35. - E7F13

What is the function of taps in a digital signal processing filter?

Select	Answer
A	Select the point at which baseband signals are generated
B	Provide access for debugging software
C	To reduce excess signal pressure levels
D	Provide incremental signal delays for filter algorithms

36. - E7G04

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

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

37. - E7H06

Which of the following oscillator circuits are commonly used in VFOs?

Select	Answer
A	Pierce and Zener
B	Armstrong and deForest
C	Colpitts and Hartley
D	Negative feedback and balanced feedback

38. - E8A08

Why would a direct or flash conversion analog-to-digital converter be useful for a software defined radio?

Select	Answer
A	Immunity to out of sequence coding reduces spurious responses
B	All of these choices are correct
C	Very low power consumption decreases frequency drift
D	Very high speed allows digitizing high frequencies

39. - E8B04

What is the modulation index of an FM-phone signal having a maximum carrier deviation of plus or minus 6 kHz when modulated with a 2 kHz modulating frequency?

Select	Answer
A	6000
B	3
C	1/3
D	2000

40. - E8C05

What is the necessary bandwidth of a 13-WPM international Morse code transmission?

Select	Answer
A	Approximately 26 Hz
B	Approximately 13 Hz
C	Approximately 104 Hz
D	Approximately 52 Hz

41. - E8D06

Which of the following indicates likely overmodulation of an AFSK signal such as PSK or MFSK?

Select	Answer
A	Harmonics on higher bands
B	High reflected power
C	Strong ALC action
D	Rapid signal fading

42. - E9A03

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

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

43. - E9B08

How can the approximate beam-width in a given plane of a directional antenna be determined?

Select	Answer
A	Measure the ratio of the signal strengths of the radiated power lobes from the front and side of the antenna
B	Measure the ratio of the signal strengths of the radiated power lobes from the front and rear of the antenna
C	Note the two points where the signal strength of the antenna is 3 dB less than maximum and compute the angular difference
D	Draw two imaginary lines through the ends of the elements and measure the angle between the lines

44. - E9C05

What is an OCFD antenna?

Select	Answer
A	A multiband dipole antenna using one-way circular polarization for frequency diversity
B	An eight band dipole antenna using octophase filters
C	A remotely tunable dipole antenna using orthogonally controlled frequency diversity
D	A dipole feed approximately 1/3 the way from one end with a 4:1 balun to provide multiband operation

45. - E9D09

What is the function of a loading coil used as part of an HF mobile antenna?

Select	Answer
A	To increase the SWR bandwidth
B	To cancel capacitive reactance
C	To lower the losses
D	To lower the Q

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 delta match
C	The epsilon match
D	The stub match

47. - E9F11

What impedance does a 1/8 wavelength transmission line present to a generator when the line is open 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 of the final generator stage
D	An inductive reactance

48. - E9G02

What type of coordinate system is used in a Smith chart?

Select	Answer
A	Resistance lines and reactance chords
B	Voltage circles and current arcs
C	Voltage lines and current chords
D	Resistance circles and reactance arcs

49. - E9H02

Which is generally true for low band (160 meter and 80 meter) receiving antennas?

Select	Answer
A	All of these choices are correct
B	Low loss coax transmission line is essential for good performance
C	They must be erected at least 1/2 wavelength above the ground to attain good directivity
D	Atmospheric noise is so high that gain over a dipole is not important

50. - E0A07

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

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

Figure E6-2