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 RF current flow between pieces of equipment
B	Reduce received noise
C	Reduce RFI to telephones and home entertainment systems
D	Lightning protection

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

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	An Environmental Assessment must be submitted to the FCC
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	A form FSD-15 must be submitted to the Department of the Interior

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

5. - E1D12

Which of the following amateur stations may transmit one-way communications?

Select	Answer
A	A space station, beacon station, or telecommand station
B	A message forwarding station or automatically controlled digital station
C	A local repeater or linked repeater station
D	All these choices are correct

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

8. - E2A06

What are Keplerian elements?

Select	Answer
A	High-emission heater filaments used in magnetron tubes
B	Encrypting codes used for spread spectrum modulation
C	Phase reversing elements in a Yagi antenna
D	Parameters that define the orbit of a satellite

9. - E2B10

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

Select	Answer
A	Tone frequency
B	Sync amplitude
C	Sync frequency
D	Tone amplitude

10. - E2C11

How should you generally identify your station when attempting to contact a DX station during a contest or in a pileup?

Select	Answer
A	Send your full call sign and grid square
B	Send only the last two letters of your call sign until you make contact
C	Send your full call sign once or twice
D	Send the call sign of the DX station three times, the words this is,then your call sign three times

11. - E2D05

What is one advantage of the JT65 mode?

Select	Answer
A	Easily copied by ear if necessary
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	Uses only a 65 Hz bandwidth

12. - E2E01

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

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

13. - E3A08

When a meteor strikes the Earth's atmosphere, a cylindrical region of free electrons is formed at what layer of the ionosphere?

Select	Answer
A	The E layer
B	The F1 layer
C	The F2 layer
D	The D layer

14. - E3B10

Why is chordal hop propagation desirable?

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

15. - E3C03

Which of the following signal paths is most likely to experience high levels of absorption when the A index or K index is elevated?

Select	Answer
A	Sporadic E
B	NVIS
C	Transequatorial
D	Polar

16. - E4A08

Which of the following measures SWR?

Select	Answer
A	An ohmmeter
B	A Q meter
C	A spectrum analyzer
D	An antenna analyzer

17. - E4B06

How much power is being absorbed by the load when a directional power meter connected between a transmitter and a terminating load reads 100 watts forward power and 25 watts reflected power?

Select	Answer
A	100 watts
B	75 watts
C	25 watts
D	125 watts

18. - E4C13

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

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

19. - E4D12

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

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

20. - E4E05

How can radio frequency interference from an AC motor be suppressed?

Select	Answer
A	By using a ground-fault current interrupter in the circuit used to power the motor
B	By installing a brute-force AC-line filter in series with the motor leads
C	By installing a high-pass filter in series with the motor's power leads
D	By installing a bypass capacitor in series with the motor leads

21. - E5A07

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

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

22. - E5B06

What is susceptance?

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

23. - E5C01

Which of the following represents capacitive reactance in rectangular notation?

Select	Answer
A	+jX
B	Delta
C	Omega
D	-jX

24. - E5D05

What is the power factor of an RL circuit having a 30-degree phase angle between the voltage and the current?

Select	Answer
A	0.866
B	1.73
C	0.577
D	0.5

25. - E6A06

What is the beta of a bipolar junction transistor?

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

26. - E6B09

What is a common use for point-contact diodes?

Select	Answer
A	As an RF detector
B	As a constant current source
C	As a high-voltage rectifier
D	As a constant voltage source

27. - E6C11

In Figure E6-3, what is the schematic symbol for the NOT operation (inverter)?

Select	Answer
A	2
B	5
C	6
D	4

28. - E6D03

Which of the following is an aspect of the piezoelectric effect?

Select	Answer
A	Mechanical deformation of material by the application of a magnetic field
B	Increased conductivity in the presence of light
C	Mechanical deformation of material by the application of a voltage
D	Generation of electrical energy in the presence of light

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 resistor and/or RF choke connected to the amplifier output lead
C	Through a capacitor and RF choke connected to the amplifier input lead
D	MMICs require no operating bias

30. - E6F06

Which of these materials is most commonly used to create photoconductive devices?

Select	Answer
A	A heavy metal
B	A liquid semiconductor
C	A crystalline semiconductor
D	An ordinary metal

31. - E7A09

What logical operation is performed by an exclusive NOR gate?

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

32. - E7B08

How can an RF power amplifier be neutralized?

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

33. - E7C08

Which of the following factors has the greatest effect on the bandwidth and response shape of a crystal ladder filter?

Select	Answer
A	The amplitude of the signals passing through the filter
B	The DC voltage applied to the quartz crystal
C	The relative frequencies of the individual crystals
D	The gain of the RF stage preceding the filter

34. - E7D13

What is the equation for calculating power dissipated by a series linear voltage regulator?

Select	Answer
A	Output voltage multiplied by output current
B	Input voltage multiplied by input current
C	Input voltage divided by output current
D	Voltage difference from input to output multiplied by output current

35. - E7E01

Which of the following can be used to generate FM phone emissions?

Select	Answer
A	A reactance modulator on the oscillator
B	A balanced modulator on the audio amplifier
C	A balanced modulator on the oscillator
D	A reactance modulator on the final amplifier

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

37. - E7G01

What is the typical output impedance of an op-amp?

Select	Answer
A	100 ohms
B	Very low
C	1000 ohms
D	Very high

38. - E7H03

How is positive feedback supplied in a Hartley oscillator?

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

39. - E8A11

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

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

40. - E8B03

What is the modulation index of an FM-phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency when the modulating frequency is 1000 Hz?

Select	Answer
A	3000
B	1000
C	3
D	0.3

41. - E8C08

How does ARQ accomplish error correction?

Select	Answer
A	Special polynomial codes provide automatic correction
B	Special binary codes provide automatic correction
C	If errors are detected, redundant data is substituted
D	If errors are detected, a retransmission is requested

42. - E8D11

What is one advantage of using ASCII code for data communications?

Select	Answer
A	It contains fewer information bits per character than any other code
B	It is possible to transmit both upper and lower case text
C	It uses one character as a shift code to send numeric and special characters
D	It includes built-in error correction features

43. - E9A10

Which of the following improves the efficiency of a ground-mounted quarter-wave vertical antenna?

Select	Answer
A	All these choices are correct
B	Isolating the coax shield from ground
C	Shortening the radiating element
D	Installing a radial system

44. - E9B04

What is the front-to-back ratio of the radiation pattern shown in Figure E92?

Select	Answer
A	15 dB
B	38 dB
C	28 dB
D	3 dB

45. - E9C12

Which of the following describes an Extended Double Zepp antenna?

Select	Answer
A	A wideband vertical antenna constructed from precisely tapered aluminum tubing
B	A center-fed 1.25-wavelength antenna (two 5/8-wave elements in phase)
C	A portable antenna erected using two push support poles
D	An end-fed folded dipole antenna

46. - E9D05

What usually occurs if a Yagi antenna is designed solely for maximum forward gain?

Select	Answer
A	The SWR is reduced
B	The front-to-back ratio increases
C	The frequency response is widened over the whole frequency band
D	The front-to-back ratio decreases

47. - E9E11

What is the primary purpose of phasing lines when used with an antenna having multiple driven elements?

Select	Answer
A	It prevents reflected power from traveling back down the feed line and causing harmonic radiation from the transmitter
B	It allows single-band antennas to operate on other bands
C	It creates a low-angle radiation pattern
D	It ensures that each driven element operates in concert with the others to create the desired antenna pattern

48. - E9F04

What impedance does a 1/2-wavelength transmission line present to a generator when the line is shorted at the far end?

Select	Answer
A	Very high impedance
B	The same as the characteristic impedance of the line
C	Very low impedance
D	The same as the output impedance of the generator

49. - E9G09

What third family of circles is often added to a Smith chart during the process of solving problems?

Select	Answer
A	Radiation-pattern circles
B	Coaxial-length circles
C	Antenna-length circles
D	Standing wave ratio circles

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

Figure E6-3