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

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1. - E0A05

What is one of the potential hazards of operating in the amateur radio microwave bands?

Select	Answer
A	Microwaves often travel long distances by ionospheric reflection
B	The high gain antennas commonly used can result in high exposure levels
C	Microwaves are ionizing radiation
D	The extremely high frequency energy can damage the joints of antenna structures

2. - E1A01

Which of the following carrier frequencies is illegal for LSB AFSK emissions on the 17 meter band RTTY and data segment of 18.068 to 18.110 MHz?

Select	Answer
A	18.107 MHz
B	18.100 MHz
C	18.068 MHz
D	18.110 MHz

3. - E1B10

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

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

4. - E1C06

Which of the following is required in order to operate in accordance with CEPT rules in foreign countries where permitted?

Select	Answer
A	The U.S. embassy must approve of your operation
B	You must identify in the official language of the country in which you are operating
C	You must bring a copy of FCC Public Notice DA 16-1048
D	You must append "/CEPT" to your call sign

5. - E1D09

Which UHF amateur bands have frequencies authorized for space stations?

Select	Answer
A	70 cm only
B	70 cm and 13 cm
C	33 cm and 13 cm
D	70 cm and 33 cm

6. - E1E12

What must the VE team do with the application form if the examinee does not pass the exam?

Select	Answer
A	Return the application document to the examinee
B	Send the application form to the FCC and inform the FCC of the grade
C	Destroy the application form
D	Maintain the application form with the VEC's records

7. - E1F01

On what frequencies are spread spectrum transmissions permitted?

Select	Answer
A	Only on amateur frequencies above 420 MHz
B	Only on amateur frequencies above 50 MHz
C	Only on amateur frequencies above 222 MHz
D	Only on amateur frequencies above 144 MHz

8. - E2A08

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

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

9. - E2B12

What signals SSTV receiving software to begin a new picture line?

Select	Answer
A	Elapsed time
B	Specific tone frequencies
C	Specific tone amplitudes
D	A two-tone signal

10. - E2C03

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

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

11. - E2D08

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

Select	Answer
A	Unnumbered Information
B	Connect
C	Acknowledgement
D	Disconnect

12. - E2E13

Which of these digital modes has the fastest data throughput under clear communication conditions?

Select	Answer
A	PSK31
B	170 Hz shift, 45 baud RTTY
C	300 baud packet
D	AMTOR

13. - E3A13

Which of these emission modes is best for auroral propagation?

Select	Answer
A	SSB
B	FM
C	CW
D	RTTY

14. - E3B02

What is the approximate maximum range for signals using transequatorial propagation?

Select	Answer
A	1000 miles
B	7500 miles
C	5000 miles
D	2500 miles

15. - E3C07

Which of the following descriptors indicates the greatest solar flare intensity?

Select	Answer
A	Class X
B	Class A
C	Class B
D	Class M

16. - E4A08

Which of the following measures SWR?

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

17. - E4B04

Which S parameter represents input port return loss or reflection coefficient (equivalent to VSWR)?

Select	Answer
A	S21
B	S12
C	S22
D	S11

18. - E4C03

What is the term for the suppression in an FM receiver of one signal by another stronger signal on the same frequency?

Select	Answer
A	Cross-modulation interference
B	Capture effect
C	Frequency discrimination
D	Desensitization

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. - E4E09

What undesirable effect can occur when using an IF noise blanker?

Select	Answer
A	Nearby signals may appear to be excessively wide even if they meet emission standards
B	Received audio in the speech range might have an echo effect
C	The audio frequency bandwidth of the received signal might be compressed
D	FM signals can no longer be demodulated

21. - E5A03

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

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

22. - E5B12

What is admittance?

Select	Answer
A	The turns ratio of a transformer
B	The inverse of Q factor
C	The inverse of impedance
D	The term for the gain of a field effect transistor

23. - E5C06

What does the impedance 50-j25 represent?

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

24. - E5D06

In what direction is the magnetic field oriented about a conductor in relation to the direction of electron flow?

Select	Answer
A	In the same direction as the current
B	In all directions; omni-directional
C	In a direction opposite to the current
D	In a circle around the conductor

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	Alpha rejection frequency
B	Alpha cutoff frequency
C	Corner frequency
D	Beta cutoff frequency

26. - E6B03

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

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

27. - E6C10

In Figure E6-3, what is the schematic symbol for a NOR gate?

Select	Answer
A	2
B	4
C	3
D	1

28. - E6D06

What core material property determines the inductance of an inductor?

Select	Answer
A	Reactivity
B	Permeability
C	Resistance
D	Thermal impedance

29. - E6E02

Which of the following device packages is a through-hole type?

Select	Answer
A	SOT
B	DIP
C	PLCC
D	Ball grid array

30. - E6F09

What is the efficiency of a photovoltaic cell?

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

31. - E7A02

What is the function of a decade counter?

Select	Answer
A	It decodes a decimal number for display on a seven-segment LED display
B	It produces one output pulse for every 10 input pulses
C	It decodes a binary number for display on a seven-segment LED display
D	It produces 10 output pulses for every input pulse

32. - E7B01

For what portion of the signal cycle does each active element in a push-pull Class AB amplifier conduct?

Select	Answer
A	Less than 180 degrees
B	The entire cycle
C	More than 180 degrees but less than 360 degrees
D	Exactly 180 degrees

33. - E7C04

How does an impedance-matching circuit transform a complex impedance to a resistive impedance?

Select	Answer
A	It introduces negative resistance to cancel the resistive part of impedance
B	It introduces transconductance to cancel the reactive part of impedance
C	Reactive currents are dissipated in matched resistances
D	It cancels the reactive part of the impedance and changes the resistive part to a desired value

34. - E7D01

How does a linear electronic voltage regulator work?

Select	Answer
A	The conduction of a control element is varied to maintain a constant output voltage
B	The control element duty cycle is proportional to the line or load conditions
C	It eliminates the need for a pass transistor
D	It has a ramp voltage as its output

35. - E7E08

What are the principal frequencies that appear at the output of a mixer circuit?

Select	Answer
A	Two and four times the original frequency
B	1.414 and 0.707 times the input frequency
C	The two input frequencies along with their sum and difference frequencies
D	The square root of the product of input frequencies

36. - E7F08

What is the function of decimation?

Select	Answer
A	Reducing the effective sample rate by removing samples
B	Attenuating the signal
C	Removing unnecessary significant digits
D	Converting data to binary code decimal form

37. - E7G03

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

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

38. - E7H03

How is positive feedback supplied in a Hartley oscillator?

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

39. - E8A01

What is the name of the process that shows that a square wave is made up of a sine wave plus all its odd harmonics?

Select	Answer
A	Fourier analysis
B	Vector analysis
C	Numerical analysis
D	Differential analysis

40. - E8B10

What is frequency division multiplexing?

Select	Answer
A	The transmitted signal jumps from band to band at a predetermined rate
B	Two or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter
C	Two or more information streams are merged into a baseband, which then modulates the transmitter
D	The transmitted signal is divided into packets of information

41. - E8C04

What technique minimizes the bandwidth of a PSK31 signal?

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

42. - E8D07

What is a common cause of overmodulation of AFSK signals?

Select	Answer
A	Excessive transmit audio levels
B	Excessive numbers of retries
C	Ground loops
D	Bit errors in the modem

43. - E9A05

What is included in the total resistance of an antenna system?

Select	Answer
A	Radiation resistance plus loss resistance
B	Transmission-line resistance plus radiation resistance
C	Radiation resistance plus space impedance
D	Radiation resistance plus transmission resistance

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

45. - E9C06

What is the effect of adding a terminating resistor to a rhombic antenna?

Select	Answer
A	It changes the radiation pattern from horizontal to vertical polarization
B	It changes the radiation pattern from bidirectional to unidirectional
C	It decreases the ground loss
D	It reflects the standing waves on the antenna elements back to the transmitter

46. - E9D02

How can linearly polarized Yagi antennas be used to produce circular polarization?

Select	Answer
A	Stack two Yagis fed in phase to form an array with the respective elements in parallel planes
B	Arrange two Yagis collinear to each other with the driven elements fed 180 degrees out of phase
C	Arrange two Yagis perpendicular to each other with the driven elements at the same point on the boom fed 90 degrees out of phase
D	Stack two Yagis fed 90 degrees out of phase to form an array with the respective elements in parallel planes

47. - E9E01

What system matches a higher-impedance transmission line to a lower-impedance antenna by connecting the line to the driven element in two places spaced a fraction of a wavelength each side of element center?

Select	Answer
A	The stub matching system
B	The gamma matching system
C	The delta matching system
D	The omega matching system

48. - E9F06

What is the approximate physical length of an air-insulated, parallel conductor transmission line that is electrically 1/2 wavelength long at 14.10 MHz?

Select	Answer
A	10.6 meters
B	7.0 meters
C	13.3 meters
D	8.5 meters

49. - E9G10

What do the arcs on a Smith chart represent?

Select	Answer
A	Points with constant resistance
B	Points with constant reactance
C	SWR
D	Frequency

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

Figure E6-3