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

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1. - E0A08

What does SAR measure?

Select	Answer
A	The rate of RF energy reflected from stationary terrain
B	Signal Amplification Rating
C	Synthetic Aperture Ratio of the human body
D	The rate at which RF energy is absorbed by the body

2. - E1A06

Where must the carrier frequency of a CW signal be set to comply with FCC rules for 60 meter operation?

Select	Answer
A	On any frequency where the signal's sidebands are within the channel
B	At the center frequency of the channel
C	At the lowest frequency of the channel
D	At the highest frequency of the channel

3. - E1B10

What frequencies are authorized to an amateur station operating under RACES rules?

Select	Answer
A	Military Auxiliary Radio System (MARS) channels
B	Specific local government channels
C	Specific segments in the amateur service MF, HF, VHF and UHF bands
D	All amateur service frequencies authorized to the control operator

4. - E1C07

At what level below a signal's mean power level is its bandwidth determined according to FCC rules?

Select	Answer
A	23 dB
B	3 dB
C	6 dB
D	26 dB

5. - E1D11

Which amateur stations are eligible to operate as Earth stations?

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

6. - E1E03

What is a Volunteer Examiner Coordinator?

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

7. - E1F04

Which of the following geographic descriptions approximately describes "Line A"?

Select	Answer
A	A line roughly parallel to and south of the border between the U.S. and Canada
B	A line roughly parallel to and north of the border between the U.S. and Mexico
C	A line roughly parallel to and west of the U.S. Atlantic coastline
D	A line roughly parallel to and east of the U.S. Pacific coastline

8. - E2A05

What do the letters in a satellite's mode designator specify?

Select	Answer
A	The location of the ground control station
B	Power limits for uplink and downlink transmissions
C	The uplink and downlink frequency ranges
D	The polarization of uplink and downlink signals

9. - E2B01

How many times per second is a new frame transmitted in a fast-scan (NTSC) television system?

Select	Answer
A	30
B	120
C	60
D	90

10. - E2C10

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

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

11. - E2D08

What type of packet frame is used to transmit APRS beacon data?

Select	Answer
A	Disconnect
B	Connect
C	Acknowledgement
D	Unnumbered Information

12. - E2E01

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

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

13. - E3A01

What is the approximate maximum separation measured along the surface of the Earth between two stations communicating by EME?

Select	Answer
A	12,000 miles, if the moon is visible by both stations
B	5000 miles, if the moon is at perigee
C	500 miles, if the moon is at perigee
D	2000 miles, if the moon is at apogee

14. - E3B10

Why is chordal hop propagation desirable?

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

15. - E3C04

What does the value of Bz (B sub Z) represent?

Select	Answer
A	Direction and strength of the interplanetary magnetic field
B	Geomagnetic field stability
C	Duration of long-delayed echoes
D	Critical frequency for vertical transmissions

16. - E4A02

Which of the following parameters does a spectrum analyzer display on the vertical and horizontal axes?

Select	Answer
A	RF amplitude and time
B	SWR and time
C	RF amplitude and frequency
D	SWR and frequency

17. - E4B11

Which of the following can be measured with a vector network analyzer?

Select	Answer
A	Reflection coefficient
B	Input impedance
C	Output impedance
D	All these choices are correct

18. - E4C11

Why can an attenuator be used to reduce receiver overload on the lower frequency HF bands with little or no impact on signal-to-noise ratio?

Select	Answer
A	The attenuator has a low-pass filter to increase the strength of lower frequency signals
B	The attenuator has a noise filter to suppress interference
C	Atmospheric noise is generally greater than internally generated noise even after attenuation
D	Signals are attenuated separately from the noise

19. - E4D12

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

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

20. - E4E10

What might be the cause of a loud roaring or buzzing AC line interference that comes and goes at intervals?

Select	Answer
A	A malfunctioning illuminated advertising display
B	A defective doorbell or doorbell transformer inside a nearby residence
C	Arcing contacts in a thermostatically controlled device
D	All these choices are correct

21. - E5A03

What is the magnitude of the impedance of a series RLC circuit at resonance?

Select	Answer
A	High, as compared to the circuit resistance
B	Approximately equal to capacitive reactance
C	Approximately equal to inductive reactance
D	Approximately equal to circuit resistance

22. - 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	14.0 degrees with the voltage lagging the current
B	14.0 degrees with the voltage leading the current
C	68.2 degrees with the voltage lagging the current
D	68.2 degrees with the voltage leading the current

23. - E5C06

What does the impedance 50-j25 represent?

Select	Answer
A	25 ohms resistance in series with 50 ohms inductive reactance
B	50 ohms resistance in series with 25 ohms capacitive reactance
C	25 ohms resistance in series with 50 ohms capacitive reactance
D	50 ohms resistance in series with 25 ohms inductive reactance

24. - E5D09

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

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

25. - E6A03

Why does a PN-junction diode not conduct current when reverse biased?

Select	Answer
A	Excess holes in P-type material combine with the electrons in N-type material, converting the entire diode into an insulator
B	Holes in P-type material and electrons in the N-type material are separated by the applied voltage, widening the depletion region
C	Only N-type semiconductor material can conduct current
D	Only P-type semiconductor material can conduct current

26. - E6B10

In Figure E6-2, what is the schematic symbol for a light-emitting diode?

Select	Answer
A	1
B	7
C	5
D	6

27. - E6C05

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

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

28. - E6D11

Which type of core material decreases inductance when inserted into a coil?

Select	Answer
A	Powdered iron
B	Ferrite
C	Brass
D	Ceramic

29. - E6E11

What is a characteristic of DIP packaging used for integrated circuits?

Select	Answer
A	A total of two rows of connecting pins placed on opposite sides of the package (Dual In-line Package)
B	Package mounts in a direct inverted position
C	Low leakage doubly insulated package
D	Two chips in each package (Dual In Package)

30. - E6F10

What is the most common type of photovoltaic cell used for electrical power generation?

Select	Answer
A	Silicon
B	Cadmium Sulfide
C	Copper oxide
D	Selenium

31. - E7A08

What logical operation does an OR gate perform?

Select	Answer
A	It produces logic 1 at its output if any or all inputs are logic 1
B	It produces logic 0 at its output if all inputs are logic 1
C	It produces logic 1 at its output if all inputs are logic 0
D	It only produces logic 0 at its output when all inputs are logic 1

32. - E7B18

What is a characteristic of a grounded-grid amplifier?

Select	Answer
A	High power gain
B	Low bandwidth
C	High filament voltage
D	Low input impedance

33. - E7C11

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

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

34. - E7D14

What is the purpose of connecting equal-value resistors across power supply filter capacitors connected in series?

Select	Answer
A	Provide a minimum load on the supply
B	Discharge the capacitors when voltage is removed
C	Equalize the voltage across each capacitor
D	All these choices are correct

35. - E7E07

What is meant by the term "baseband" in radio communications?

Select	Answer
A	The frequency range occupied by a message signal prior to modulation
B	The basic oscillator frequency in an FM transmitter that is multiplied to increase the deviation and carrier frequency
C	The unmodulated bandwidth of the transmitted signal
D	The lowest frequency band that the transmitter or receiver covers

36. - E7F09

Why is an anti-aliasing digital filter required in a digital decimator?

Select	Answer
A	It removes high-frequency signal components that would otherwise be reproduced as lower frequency components
B	It peaks the response of the decimator, improving bandwidth
C	It notches out the sampling frequency to avoid sampling errors
D	It removes low-frequency signal components to eliminate the need for DC restoration

37. - E7G11

What absolute voltage gain can be expected from the circuit in Figure E7-3 when R1 is 3300 ohms and RF is 47 kilohms?

Select	Answer
A	7
B	28
C	0.07
D	14

38. - E7H11

What are the major spectral impurity components of direct digital synthesizers?

Select	Answer
A	Digital conversion noise
B	Nyquist limit noise
C	Broadband noise
D	Spurious signals at discrete frequencies

39. - E8A07

What determines the PEP-to-average power ratio of a single-sideband phone signal?

Select	Answer
A	The degree of carrier suppression
B	Amplifier gain
C	The frequency of the modulating signal
D	Speech characteristics

40. - E8B02

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

Select	Answer
A	It does not depend on the RF carrier frequency
B	It increases as the RF carrier frequency increases
C	It decreases as the RF carrier frequency increases
D	It varies with the square root of the RF carrier frequency

41. - E8C12

What factors affect the bandwidth of a transmitted CW signal?

Select	Answer
A	Modulation index and output power
B	IF bandwidth and Q
C	All these choices are correct
D	Keying speed and shape factor (rise and fall time)

42. - E8D03

How does the spread spectrum technique of frequency hopping work?

Select	Answer
A	If interference is detected by the receiver it will signal the transmitter to change frequencies
B	A binary bit stream is used to shift the phase of an RF carrier very rapidly in a pseudorandom sequence
C	The frequency of the transmitted signal is changed very rapidly according to a pseudorandom sequence also used by the receiving station
D	If interference is detected by the receiver it will signal the transmitter to wait until the frequency is clear

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	3.85 dB
B	2.79 dB
C	6.0 dB
D	8.15 dB

44. - E9B09

What type of computer program technique is commonly used for modeling antennas?

Select	Answer
A	Calculus differentiation with respect to physical properties
B	Graphical analysis
C	Mutual impedance analysis
D	Method of Moments

45. - E9C01

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed 180 degrees out of phase?

Select	Answer
A	A figure-8 broadside to the axis of the array
B	A figure-8 oriented along the axis of the array
C	Omni-directional
D	Cardioid

46. - E9D06

What happens to the SWR bandwidth when one or more loading coils are used to resonate an electrically short antenna?

Select	Answer
A	It is increased
B	It is unchanged if the loading coil is located at the feed point
C	It is unchanged if the loading coil is located at a voltage maximum point
D	It is decreased

47. - 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 stub match
B	The epsilon match
C	The delta match
D	The gamma match

48. - E9F05

What is the approximate physical length of a solid polyethylene dielectric coaxial transmission line that is electrically 1/4 wavelength long at 14.1 MHz?

Select	Answer
A	10.6 meters
B	4.3 meters
C	3.5 meters
D	5.3 meters

49. - E9G01

Which of the following can be calculated using a Smith chart?

Select	Answer
A	Antenna radiation pattern
B	Radio propagation
C	Radiation resistance
D	Impedance along transmission lines

50. - E9H02

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

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

Figure E6-2

Figure E7-3