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

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1. - E0A09

Which insulating material commonly used as a thermal conductor for some types of electronic devices is extremely toxic if broken or crushed and the particles are accidentally inhaled?

Select	Answer
A	Uranium Hexafluoride
B	Mica
C	Beryllium Oxide
D	Zinc oxide

2. - E1A02

When using a transceiver that displays the carrier frequency of phone signals, which of the following displayed frequencies represents the lowest frequency at which a properly adjusted LSB emission will be totally within the band?

Select	Answer
A	1 kHz above the lower band edge
B	3 kHz above the lower band edge
C	300 Hz above the lower band edge
D	The exact lower band edge

3. - 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 except a Technician Class
C	Any FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)
D	Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served

4. - E1C07

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

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

5. - E1D01

What is the definition of telemetry?

Select	Answer
A	One-way transmission of measurements at a distance from the measuring instrument
B	One-way transmission that initiates, modifies, or terminates the functions of a device at a distance
C	Two-way transmissions in excess of 1000 feet
D	Two-way transmissions of data

6. - E1E01

For which types of out-of-pocket expenses do the Part 97 rules state that VEs and VECs may be reimbursed?

Select	Answer
A	No expenses are authorized for reimbursement
B	Preparing, processing, administering, and coordinating an examination for an amateur radio operator license
C	Teaching an amateur operator license examination preparation course
D	Providing amateur operator license examination preparation training materials

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 total money involved does not exceed $25
D	When the control operator is employed by the FCC or another government agency

8. - E2A08

Why should effective radiated power to a satellite that uses a linear transponder be limited?

Select	Answer
A	To avoid reducing the downlink power to all other users
B	To avoid interfering with terrestrial QSOs
C	To prevent creating errors in the satellite telemetry
D	To prevent the satellite from emitting out-of-band signals

9. - E2B07

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

Select	Answer
A	Luminance
B	Chroma
C	Hue
D	Spectral intensity

10. - E2C05

What is the function of a DX QSL Manager?

Select	Answer
A	To allocate frequencies for DXpeditions
B	To run a net to allow many stations to contact a rare DX station
C	To handle the receiving and sending of confirmation cards for a DX station
D	To relay calls to and from a DX station

11. - E2D08

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

Select	Answer
A	Acknowledgement
B	Unnumbered Information
C	Connect
D	Disconnect

12. - E2E02

What do the letters FEC mean as they relate to digital operation?

Select	Answer
A	First Error Correction
B	Final Error Correction
C	Fatal Error Correction
D	Forward Error Correction

13. - E3A10

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

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

14. - E3B12

What is the primary characteristic of chordal hop propagation?

Select	Answer
A	Propagation away from the great circle bearing between stations
B	Signals reflected back toward the transmitting station
C	Propagation across the geomagnetic equator
D	Successive ionospheric refractions without an intermediate reflection from the ground

15. - E3C13

What type of polarization is best for ground-wave propagation?

Select	Answer
A	Circular
B	Horizontal
C	Elliptical
D	Vertical

16. - E4A09

Which of the following is good practice when using an oscilloscope probe?

Select	Answer
A	Never use a DC-coupled probe to measure an AC circuit
B	All these choices are correct
C	Keep the signal ground connection of the probe as short as possible
D	Never use a high-impedance probe to measure a low-impedance circuit

17. - E4B11

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

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

18. - E4C07

What does the MDS of a receiver represent?

Select	Answer
A	The minimum discernible signal
B	The meter display sensitivity
C	The multiplex distortion stability
D	The maximum detectable spectrum

19. - E4D07

Which of the following reduces the likelihood of receiver desensitization?

Select	Answer
A	Decrease the RF bandwidth of the receiver
B	Raise the receiver IF frequency
C	Switch from fast AGC to slow AGC
D	Increase the receiver front end gain

20. - E4E11

What could cause local AM broadcast band signals to combine to generate spurious signals in the MF or HF bands?

Select	Answer
A	You are receiving skywave signals from a distant station
B	Nearby corroded metal joints are mixing and re-radiating the broadcast signals
C	Your station receiver IF amplifier stage is defective
D	One or more of the broadcast stations is transmitting an over-modulated signal

21. - E5A06

What is the magnitude of the circulating current within the components of a parallel LC circuit at resonance?

Select	Answer
A	It equals 2 multiplied by pi, multiplied by frequency, multiplied by inductance
B	It equals 1 divided by the quantity 2 times pi, multiplied by the square root of inductance L multiplied by capacitance C
C	It is at a maximum
D	It is at a minimum

22. - E5B10

What is the relationship between the AC current through an inductor and the voltage across an inductor?

Select	Answer
A	Voltage leads current by 90 degrees
B	Voltage and current are in phase
C	Current leads voltage by 90 degrees
D	Voltage and current are 180 degrees out of phase

23. - E5C03

Which of the following represents an inductive reactance in polar coordinates?

Select	Answer
A	A negative magnitude
B	A positive phase angle
C	A positive magnitude
D	A negative phase angle

24. - E5D15

What is the power factor of an RL circuit having a 45-degree phase angle between the voltage and the current?

Select	Answer
A	0.707
B	1.0
C	0.866
D	0.5

25. - E6A08

What term indicates the frequency at which the grounded-base current gain of a transistor has decreased to 0.7 of the gain obtainable at 1 kHz?

Select	Answer
A	Beta cutoff frequency
B	Alpha cutoff frequency
C	Corner frequency
D	Alpha rejection frequency

26. - E6B11

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

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

27. - E6C11

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

Select	Answer
A	5
B	2
C	6
D	4

28. - E6D10

What is a primary advantage of using a toroidal core instead of a solenoidal core in an inductor?

Select	Answer
A	Toroidal cores confine most of the magnetic field within the core material
B	Toroidal cores make it easier to couple the magnetic energy into other components
C	Toroidal cores exhibit greater hysteresis
D	Toroidal cores have lower Q characteristics

29. - E6E03

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

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

30. - E6F02

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

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

31. - E7A10

What is a truth table?

Select	Answer
A	A diagram showing logic states when the digital device output is true
B	A table of logic symbols that indicate the high logic states of an op-amp
C	A list of inputs and corresponding outputs for a digital device
D	A table of logic symbols that indicate the logic states of an op-amp

32. - E7B05

What can be done to prevent unwanted oscillations in an RF power amplifier?

Select	Answer
A	Install parasitic suppressors and/or neutralize the stage
B	Tune the stage for maximum SWR
C	Use a phase inverter in the output filter
D	Tune both the input and output for maximum power

33. - E7C05

Which filter type is described as having ripple in the passband and a sharp cutoff?

Select	Answer
A	A passive op-amp filter
B	A Butterworth filter
C	An active LC filter
D	A Chebyshev filter

34. - E7D12

What is the dropout voltage of an analog voltage regulator?

Select	Answer
A	Minimum input-to-output voltage required to maintain regulation
B	Maximum output voltage drops when the input voltage is varied over its specified range
C	Minimum input voltage for rated power dissipation
D	Maximum that the output voltage may decrease at rated load

35. - E7E01

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

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

36. - E7F04

What is a common method of generating an SSB signal using digital signal processing?

Select	Answer
A	Mixing products are converted to voltages and subtracted by adder circuits
B	A frequency synthesizer removes the unwanted sidebands
C	Signals are combined in quadrature phase relationship
D	Varying quartz crystal characteristics emulated in digital form

37. - E7G07

What magnitude of voltage gain can be expected from the circuit in Figure E73 when R1 is 10 ohms and RF is 470 ohms?

Select	Answer
A	24
B	0.21
C	94
D	47

38. - E7H08

Which of the following components can be used to reduce thermal drift in crystal oscillators?

Select	Answer
A	Toroidal inductors
B	NP0 capacitors
C	Wirewound resistors
D	Non-inductive resistors

39. - E8A11

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

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

40. - E8B07

Orthogonal Frequency Division Multiplexing is a technique used for which type of amateur communication?

Select	Answer
A	OFDM signals are not allowed on amateur bands
B	EME
C	High-speed digital modes
D	Extremely low-power contacts

41. - E8C03

Why should phase-shifting of a PSK signal be done at the zero crossing of the RF signal?

Select	Answer
A	To minimize bandwidth
B	All these choices are correct
C	To improve carrier suppression
D	To simplify modulation

42. - E8D11

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

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

43. - E9A02

What is the effective radiated power relative to a dipole of a repeater station with 150 watts transmitter power output, 2 dB feed line loss, 2.2 dB duplexer loss, and 7 dBd antenna gain?

Select	Answer
A	286 watts
B	78.7 watts
C	1977 watts
D	420 watts

44. - E9B10

What is the principle of a Method of Moments analysis?

Select	Answer
A	A wire is modeled as a series of segments, each having a distinct value of voltage across it
B	A wire is modeled as a single sine-wave voltage source
C	A wire is modeled as a single sine-wave current generator
D	A wire is modeled as a series of segments, each having a uniform value of current

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

46. - E9D04

Why should an HF mobile antenna loading coil have a high ratio of reactance to resistance?

Select	Answer
A	To minimize losses
B	To swamp out harmonics
C	To minimize the Q
D	To lower the radiation angle

47. - E9E06

Which of these feed line impedances would be suitable for constructing a quarter-wave Q-section for matching a 100-ohm loop to 50-ohm feed line?

Select	Answer
A	75 ohms
B	62 ohms
C	50 ohms
D	450 ohms

48. - E9F03

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

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

49. - E9G04

What are the two families of circles and arcs that make up a Smith chart?

Select	Answer
A	Resistance and reactance
B	Resistance and voltage
C	Voltage and impedance
D	Reactance and voltage

50. - E9H04

What is an advantage of placing a grounded electrostatic shield around a small loop direction-finding antenna?

Select	Answer
A	It adds capacitive loading, increasing the bandwidth of the antenna
B	It eliminates unbalanced capacitive coupling to the surroundings, improving the nulls
C	It eliminates tracking errors caused by strong out-of-band signals
D	It increases signal strength by providing a better match to the feed line

Figure E6-3