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

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1. - 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 RF current flow between pieces of equipment
D	Reduce received noise

2. - E1A11

Which of the following describes authorization or licensing required when operating an amateur station aboard a U.S.-registered vessel in international waters?

Select	Answer
A	Any amateur license with an FCC Marine or Aircraft endorsement
B	Any FCC-issued amateur license
C	An unrestricted Radiotelephone Operator Permit
D	Only General Class or higher amateur licenses

3. - E1B04

What must be done before placing an amateur station within an officially designated wilderness area or wildlife preserve, or an area listed in the National Register of Historic Places?

Select	Answer
A	A form FSD-15 must be submitted to the Department of the Interior
B	A letter of intent must be filed with the Environmental Protection Agency
C	A proposal must be submitted to the National Park Service
D	An Environmental Assessment must be submitted to the FCC

4. - E1C03

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

Select	Answer
A	Under local control there is no control operator
B	Under automatic control the control operator is not required to be present at the control point
C	Under automatic control there is no control operator
D	Under local control a control operator is not required to be present at a control point

5. - E1D11

Which amateur stations are eligible to operate as Earth stations?

Select	Answer
A	Any amateur station whose licensee has filed a pre-space notification with the FCC's International Bureau
B	Only those of Amateur Extra Class operators
C	Any amateur station, subject to the privileges of the class of operator license held by the control operator
D	Only those of General, Advanced or Amateur Extra Class operators

6. - E1E04

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

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

7. - E1F07

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

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

8. - E2A04

What is meant by the term mode? as applied to an amateur radio satellite?

Select	Answer
A	Whether the satellite is in a low earth or geostationary orbit
B	The satellite's uplink and downlink frequency bands
C	Whether the satellite is in a polar or equatorial orbit
D	The satellite's orientation with respect to the Earth

9. - E2B07

What is the name of the signal component that carries color information in NTSC video?

Select	Answer
A	Chroma
B	Hue
C	Spectral intensity
D	Luminance

10. - E2C01

What indicator is required to be used by U.S.-licensed operators when operating a station via remote control and the remote transmitter is located in the U.S.?

Select	Answer
A	No additional indicator is required
B	/ followed by the USPS two-letter abbreviation for the state in which the remote station is located
C	/ followed by the ARRL Section of the remote station
D	/R# where # is the district of the remote station

11. - E2D06

Which of the following describes a method of establishing EME contacts?

Select	Answer
A	Storing and forwarding digital messages
B	Judging optimum transmission times by monitoring beacons reflected from the moon
C	Time synchronous transmissions alternately from each station
D	High-speed CW identification to avoid fading

12. - E2E01

Which of the following types of modulation is common for data emissions below 30 MHz?

Select	Answer
A	FSK
B	Spread spectrum
C	DTMF tones modulating an FM signal
D	Pulse modulation

13. - E3A06

What might help to restore contact when DX signals become too weak to copy across an entire HF band a few hours after sunset?

Select	Answer
A	Switch to a higher frequency HF band
B	Wait 90 minutes or so for the signal degradation to pass
C	Switch to a lower frequency HF band
D	Wait 24 hours before attempting another communication on the band

14. - E3B06

Which of the following amateur bands most frequently provides long-path propagation?

Select	Answer
A	80 meters
B	20 meters
C	6 meters
D	10 meters

15. - E3C11

What does VOACAP software model?

Select	Answer
A	AC current and impedance
B	AC voltage and impedance
C	HF propagation
D	VHF radio propagation

16. - E4A10

Which of the following displays multiple digital signal states simultaneously?

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

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

18. - E4C02

Which of the following receiver circuits can be effective in eliminating interference from strong out-of-band signals?

Select	Answer
A	A front-end filter or pre-selector
B	A narrow IF filter
C	A properly adjusted product detector
D	A notch filter

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 minimum difference in dB between the levels of two FM signals that will cause one signal to block the other
C	The difference in dB between the noise floor and the level of an incoming signal that will cause 1 dB of gain compression
D	The difference in dB between the noise floor and the third-order intercept point

20. - E4E02

Which of the following types of noise can often be reduced with a digital signal processing noise filter?

Select	Answer
A	Ignition noise
B	Broadband white noise
C	Power line noise
D	All these choices are correct

21. - E5A07

What is the magnitude of the current at the input of a parallel RLC circuit at resonance?

Select	Answer
A	Maximum
B	L/R
C	R/L
D	Minimum

22. - 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	110 seconds
B	220 seconds
C	440 seconds
D	55 seconds

23. - E5C07

Where is the impedance of a pure resistance plotted on rectangular coordinates?

Select	Answer
A	On the vertical axis
B	On the horizontal axis
C	On a line through the origin, slanted at 45 degrees
D	On a horizontal line, offset vertically above the horizontal axis

24. - E5D10

How can the true power be determined in an AC circuit where the voltage and current are out of phase?

Select	Answer
A	By multiplying the apparent power by the power factor
B	By dividing the apparent power by the power factor
C	By dividing the reactive power by the power factor
D	By multiplying the reactive power by the power factor

25. - E6A06

What is the beta of a bipolar junction transistor?

Select	Answer
A	The switching speed
B	The frequency at which the current gain is reduced to 0.707
C	The breakdown voltage of the base to collector junction
D	The change in collector current with respect to base current

26. - E6B03

What type of bias is required for an LED to emit light?

Select	Answer
A	Reverse bias
B	Zero bias
C	Forward bias
D	Inductive bias

27. - E6C05

What is an advantage of CMOS logic devices over TTL devices?

Select	Answer
A	Immune to damage from static discharge
B	Lower power consumption
C	Differential output capability
D	Lower distortion

28. - E6D04

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

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

29. - E6E08

How is power supplied to the most common type of MMIC?

Select	Answer
A	Directly to the bias voltage (VCC IN) lead
B	Through a capacitor and RF choke connected to the amplifier input lead
C	MMICs require no operating bias
D	Through a resistor and/or RF choke connected to the amplifier output lead

30. - E6F09

What is the efficiency of a photovoltaic cell?

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

31. - E7A09

What logical operation is performed by an exclusive NOR gate?

Select	Answer
A	It produces logic 1 at its output only if all inputs are logic 1
B	It produces logic 0 at its output only if all inputs are logic 0
C	It produces logic 0 at its output if only one input is logic 1
D	It produces logic 1 at its output if only one input is logic 1

32. - E7B10

In Figure E7-1, what is the purpose of R1 and R2?

Select	Answer
A	Feedback
B	Voltage divider bias
C	Load resistors
D	Self bias

33. - E7C11

Which of the following describes a receiving filter's ability to reject signals occupying an adjacent channel?

Select	Answer
A	Shape factor
B	Phase response
C	Passband ripple
D	Noise factor

34. - E7D07

What is the purpose of C2 in the circuit shown in Figure E7-2?

Select	Answer
A	To self-resonate at the hum frequency
B	It is a brute force filter for the output
C	To provide fixed DC bias for Q1
D	It bypasses rectifier output ripple around D1

35. - E7E03

What is a frequency discriminator stage in a FM receiver?

Select	Answer
A	A circuit for detecting FM signals
B	A circuit for filtering two closely adjacent signals
C	An FM generator circuit
D	An automatic band-switching circuit

36. - E7F05

How frequently must an analog signal be sampled by an analog-to-digital converter so that the signal can be accurately reproduced?

Select	Answer
A	At least twice the rate of the highest frequency component of the signal
B	At the same rate as the highest frequency component of the signal
C	At least half the rate of the highest frequency component of the signal
D	At four times the rate of the highest frequency component of the signal

37. - E7G04

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

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

38. - E7H01

What are three oscillator circuits used in amateur radio equipment?

Select	Answer
A	Taft, Hartley and Pierce
B	Colpitts, Hartley and Pierce
C	Pierce, Fenner and Beane
D	Taft, Pierce and negative feedback

39. - E8A11

Which of the following is a measure of the quality of an analog-to-digital converter?

Select	Answer
A	Power factor
B	Total harmonic distortion
C	Reciprocal mixing
D	Peak envelope power

40. - E8B01

What is the modulation index of an FM signal?

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

41. - E8C01

How is Forward Error Correction implemented?

Select	Answer
A	By the receiving station repeating each block of three data characters
B	By transmitting a special algorithm to the receiving station along with the 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

42. - E8D06

What is the advantage of including parity bits in ASCII characters?

Select	Answer
A	The signal can overpower interfering signals
B	Some types of errors can be detected
C	Faster transmission rate
D	Foreign language characters can be sent

43. - E9A08

What is antenna bandwidth?

Select	Answer
A	The angle formed between two imaginary lines drawn through the element ends
B	The frequency range over which an antenna satisfies a performance requirement
C	The angle between the half-power radiation points
D	Antenna length divided by the number of elements

44. - E9B11

What is a disadvantage of decreasing the number of wire segments in an antenna model below 10 segments per half-wavelength?

Select	Answer
A	The resulting design will favor radiation of harmonic energy
B	The computed feed point impedance may be incorrect
C	Ground conductivity will not be accurately modeled
D	The antenna will become mechanically unstable

45. - E9C04

What happens to the radiation pattern of an unterminated long wire antenna as the wire length is increased?

Select	Answer
A	The lobes become more perpendicular to the wire
B	The front-to-back ratio decreases
C	The lobes align more in the direction of the wire
D	The vertical angle increases

46. - E9D08

What happens as the Q of an antenna increases?

Select	Answer
A	SWR bandwidth decreases
B	More common-mode current is present on the feed line
C	Gain is reduced
D	SWR bandwidth increases

47. - E9E08

What is a use for a Wilkinson divider?

Select	Answer
A	It is used to feed high-impedance antennas from a low-impedance source
B	It is used to divide power equally between two 50-ohm loads while maintaining 50-ohm input impedance
C	It is used to feed low-impedance loads from a high-impedance source
D	It divides the operating frequency of a transmitter signal so it can be used on a lower frequency band

48. - E9F08

Which of the following is a significant difference between foam dielectric coaxial cable and solid dielectric cable, assuming all other parameters are the same?

Select	Answer
A	Foam dielectric has lower loss per unit of length
B	All these choices are correct
C	Foam dielectric has lower safe operating voltage limits
D	Foam dielectric has higher velocity factor

49. - E9G08

What is the process of normalization with regard to a Smith chart?

Select	Answer
A	Reassigning impedance values with regard to the prime center
B	Reassigning prime center with regard to the reactance axis
C	Reassigning resistance values with regard to the reactance axis
D	Reassigning reactance values with regard to the resistance axis

50. - E9H07

Why is RF attenuation used when direction-finding?

Select	Answer
A	To increase receiver sensitivity
B	To narrow the receiver bandwidth
C	To prevent receiver overload which reduces pattern nulls
D	To compensate for isotropic directivity and the antenna effect of feed lines

Figure E7-1

Figure E7-2