US Amateur Radio - Amateur Extra (Element 4, 2020-2024) Practice Test

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1. - E0A03

Over what range of frequencies are the FCC human body RF exposure limits most restrictive?

Select	Answer
A	300 kHz to 3 MHz
B	30 to 300 MHz
C	3 to 30 MHz
D	300 to 3000 MHz

2. - E1A09

What action or actions should you take if your digital message forwarding station inadvertently forwards a communication that violates FCC rules?

Select	Answer
A	Notify the originating station that the communication does not comply with FCC rules
B	Discontinue forwarding the communication as soon as you become aware of it
C	Notify the nearest FCC Field Engineers office
D	All these choices are correct

3. - E1B08

What limitations may the FCC place on an amateur station if its signal causes interference to domestic broadcast reception, assuming that the receivers involved are of good engineering design?

Select	Answer
A	The amateur station must cease operation on all frequencies below 30 MHz
B	The amateur station must avoid transmitting during certain hours on frequencies that cause the interference
C	The amateur station must cease operation on all frequencies above 30 MHz
D	The amateur station must cease operation

4. - 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 there is no control operator
B	Under local control a control operator is not required to be present at a control point
C	Under automatic control the control operator is not required to be present at the control point
D	Under local control there is no control operator

5. - E1D03

What is a space telecommand station?

Select	Answer
A	An amateur station located in a satellite or a balloon more than 50 kilometers above the surface of the Earth
B	An amateur station located on the surface of the Earth for communication with other Earth stations by means of Earth satellites
C	An amateur station that transmits communications to initiate, modify or terminate functions of a space station
D	An amateur station that receives telemetry from a satellite or balloon more than 50 kilometers above the surface of the Earth

6. - E1E03

What is a Volunteer Examiner Coordinator?

Select	Answer
A	A person who has volunteered to prepare amateur operator license examinations
B	The person who has entered into an agreement with the FCC to be the VE session manager
C	An organization that has entered into an agreement with the FCC to coordinate, prepare, and administer amateur operator license examinations
D	A person who has volunteered to administer amateur operator license examinations

7. - E1F07

When may an amateur station send a message to a business?

Select	Answer
A	When the control operator is employed by the FCC or another government agency
B	When the total money involved does not exceed $25
C	When neither the amateur nor his or her employer has a pecuniary interest in the communications
D	When transmitting international third-party communications

8. - E2A12

What is the purpose of digital store-and-forward functions on an amateur radio satellite?

Select	Answer
A	To relay messages between satellites
B	To delay download of telemetry between satellites
C	To upload operational software for the transponder
D	To store digital messages in the satellite for later download by other stations

9. - E2B08

What technique allows commercial analog TV receivers to be used for fast-scan TV operations on the 70 cm band?

Select	Answer
A	Using USB and demodulating the signal with a computer sound card
B	Transmitting on channels shared with cable TV
C	Using converted satellite TV dishes
D	Transmitting on the abandoned TV channel 2

10. - E2C03

From which of the following bands is amateur radio contesting generally excluded?

Select	Answer
A	2 meters
B	30 meters
C	33 centimeters
D	6 meters

11. - E2D04

What technology is used to track, in real time, balloons carrying amateur radio transmitters?

Select	Answer
A	Bandwidth compressed LORAN
B	Doppler shift of beacon signals
C	Ultrasonics
D	APRS

12. - E2E09

Which of the following HF digital modes uses variable-length coding for bandwidth efficiency?

Select	Answer
A	MT63
B	RTTY
C	PACTOR
D	PSK31

13. - E3A04

What do Hepburn maps predict?

Select	Answer
A	Probability of tropospheric propagation
B	Locations of auroral reflecting zones
C	Likelihood of rain scatter along cold or warm fronts
D	Sporadic E propagation

14. - E3B03

What is the best time of day for transequatorial propagation?

Select	Answer
A	Noon
B	Morning
C	Afternoon or early evening
D	Late at night

15. - E3C01

What does the radio communication term "ray tracing" describe?

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

16. - E4A11

How should an antenna analyzer be connected when measuring antenna resonance and feed point impedance?

Select	Answer
A	Loosely couple the antenna and a dummy load to the analyzer
B	Loosely couple the analyzer near the antenna base
C	Connect the analyzer via a high-impedance transformer to the antenna
D	Connect the antenna feed line directly to the analyzer's connector

17. - E4B09

What is indicated if the current reading on an RF ammeter placed in series with the antenna feed line of a transmitter increases as the transmitter is tuned to resonance?

Select	Answer
A	The transmitter is not properly neutralized
B	There is possibly a short to ground in the feed line
C	There is an impedance mismatch between the antenna and feed line
D	There is more power going into the antenna

18. - E4C04

What is the noise figure of a receiver?

Select	Answer
A	The ratio of the noise bandwidth in hertz to the theoretical bandwidth of a resistive network
B	The ratio of thermal noise to atmospheric noise
C	The ratio of atmospheric noise to phase noise
D	The ratio in dB of the noise generated by the receiver to the theoretical minimum noise

19. - E4D01

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

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

20. - E4E04

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

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

21. - E5A14

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

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

22. - E5B06

What is susceptance?

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

23. - E5C10

Which point on Figure E5-1 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 2
B	Point 6
C	Point 4
D	Point 5

24. - E5D03

What is microstrip?

Select	Answer
A	Short lengths of coax mounted on printed circuit boards to minimize time delay between microwave circuits
B	Miniature coax used for low power applications
C	Lightweight transmission line made of common zip cord
D	Precision printed circuit conductors above a ground plane that provide constant impedance interconnects at microwave frequencies

25. - E6A11

In Figure E6-1, what is the schematic symbol for a P-channel junction FET?

Select	Answer
A	6
B	3
C	1
D	2

26. - E6B11

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

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

27. - E6C08

In Figure E6-3, what is the schematic symbol for a NAND gate?

Select	Answer
A	3
B	2
C	1
D	4

28. - E6D04

Which materials are commonly used as a core in an inductor?

Select	Answer
A	Polystyrene and polyethylene
B	Teflon and Delrin
C	Ferrite and brass
D	Cobalt and aluminum

29. - E6E05

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

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

30. - E6F02

What happens to the conductivity of a photoconductive material when light shines on it?

Select	Answer
A	It increases
B	It decreases
C	It becomes unstable
D	It stays the same

31. - E7A07

What logical operation does a NAND gate perform?

Select	Answer
A	It produces logic 0 at its output only when all inputs are logic 0
B	It produces logic 0 at its output if some but not all inputs are logic 1
C	It produces logic 0 at its output only when all inputs are logic 1
D	It produces logic 1 at its output only when all inputs are logic 1

32. - E7B04

Where on the load line of a Class A common emitter amplifier would bias normally be set?

Select	Answer
A	Where the load line intersects the voltage axis
B	At a point where the load line intersects the zero bias current curve
C	At a point where the bias resistor equals the load resistor
D	Approximately halfway between saturation and cutoff

33. - E7C02

Which of the following is a property of a T-network with series capacitors and a parallel shunt inductor?

Select	Answer
A	It is a band-pass filter
B	It is a notch filter
C	It is a high-pass filter
D	It is a low-pass filter

34. - E7D09

What is the main reason to use a charge controller with a solar power system?

Select	Answer
A	Prevention of battery undercharge
B	Prevention of battery damage due to overcharge
C	Matching of day and night charge rates
D	Control of electrolyte levels during battery discharge

35. - E7E04

What is one way a single-sideband phone signal can be generated?

Select	Answer
A	By using a reactance modulator followed by a mixer
B	By using a loop modulator followed by a mixer
C	By driving a product detector with a DSB signal
D	By using a balanced modulator followed by a filter

36. - E7F07

What function is performed by a Fast Fourier Transform?

Select	Answer
A	Converting digital signals to analog form
B	Converting analog signals to digital form
C	Converting digital signals from the time domain to the frequency domain
D	Converting 8-bit data to 16-bit data

37. - E7G02

What is ringing in a filter?

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

38. - E7H03

How is positive feedback supplied in a Hartley oscillator?

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

39. - E8A04

What is "dither" with respect to analog-to-digital converters?

Select	Answer
A	A method of decimation by randomly skipping samples
B	An error caused by irregular quantization step size
C	An abnormal condition where the converter cannot settle on a value to represent the signal
D	A small amount of noise added to the input signal to allow more precise representation of a signal over time

40. - E8B01

What is the modulation index of an FM signal?

Select	Answer
A	The type of modulation used by the transmitter
B	The ratio of modulating signal amplitude to frequency deviation
C	The ratio of frequency deviation to modulating signal frequency
D	The bandwidth of the transmitted signal divided by the modulating signal frequency

41. - E8C04

What technique minimizes the bandwidth of a PSK31 signal?

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

42. - E8D04

What is the primary effect of extremely short rise or fall time on a CW signal?

Select	Answer
A	More difficult to copy
B	The generation of RF harmonics
C	The generation of key clicks
D	Limits data speed

43. - E9A12

How much gain does an antenna have compared to a 1/2-wavelength dipole when it has 6 dB gain over an isotropic antenna?

Select	Answer
A	8.15 dB
B	2.79 dB
C	6.0 dB
D	3.85 dB

44. - E9B03

In the antenna radiation pattern shown in Figure E9-1, what is the front-to-side ratio?

Select	Answer
A	14 dB
B	24 dB
C	18 dB
D	12 dB

45. - E9C03

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed in phase?

Select	Answer
A	Cardioid
B	A Figure-8 end-fire along the axis of the array
C	A Figure-8 broadside to the axis of the array
D	Omni-directional

46. - E9D12

Which of the following would provide the best RF ground for your station?

Select	Answer
A	An electrically short connection to 3 or 4 interconnected ground rods driven into the Earth
B	An electrically short connection to a metal water pipe
C	A 50-ohm resistor connected to ground
D	An electrically short connection to 3 or 4 interconnected ground rods via a series RF choke

47. - E9E04

What is the purpose of the series capacitor in a gamma-type antenna matching network?

Select	Answer
A	To provide DC isolation between the feed line and the antenna
B	To provide a rejection notch that prevents the radiation of harmonics
C	To cancel the inductive reactance of the matching network
D	To transform the antenna impedance to a higher value

48. - E9F03

Why is the physical length of a coaxial cable transmission line shorter than its electrical length?

Select	Answer
A	Electrical signals move more slowly in a coaxial cable than in air
B	The characteristic impedance is higher in a parallel feed line
C	Skin effect is less pronounced in the coaxial cable
D	The surge impedance is higher in a parallel feed line

49. - E9G03

Which of the following is often determined using a Smith chart?

Select	Answer
A	Satellite azimuth and elevation bearings
B	Trigonometric functions
C	Beam headings and radiation patterns
D	Impedance and SWR values in transmission lines

50. - E9H02

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

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

Figure E5-1

Figure E6-1

Figure E6-3

Figure E9-1