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	Zinc oxide
B	Beryllium Oxide
C	Mica
D	Uranium Hexafluoride

2. - E1A09

What action or actions should you take if your digital message forwarding station inadvertently forwards a communication that violates FCC rules?

Select	Answer
A	Discontinue forwarding the communication as soon as you become aware of it
B	Notify the originating station that the communication does not comply with FCC rules
C	Notify the nearest FCC Field Engineers office
D	All these choices are correct

3. - E1B05

What is the National Radio Quiet Zone?

Select	Answer
A	An area surrounding the National Radio Astronomy Observatory
B	An area in Puerto Rico surrounding the Arecibo Radio Telescope
C	An area in New Mexico surrounding the White Sands Test Area
D	An area in Florida surrounding Cape Canaveral

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

5. - E1D01

What is the definition of telemetry?

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

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

7. - E1F05

Amateur stations may not transmit in which of the following frequency segments if they are located in the contiguous 48 states and north of Line A?

Select	Answer
A	222 MHz - 223 MHz
B	420 MHz - 430 MHz
C	440 MHz - 450 MHz
D	53 MHz - 54 MHz

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 prevent creating errors in the satellite telemetry
C	To avoid interfering with terrestrial QSOs
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	Spectral intensity
C	Chroma
D	Hue

10. - E2C02

Which of the following best describes the term self-spotting? in connection with HF contest operating?

Select	Answer
A	The often-prohibited practice of posting one's own call sign and frequency on a spotting network
B	The acceptable practice of manually posting the call signs of stations on a spotting network
C	An automatic method for rapidly zero beating or tuning to a station's frequency before calling that station
D	A manual technique for rapidly zero beating or tuning to a station's frequency before calling that station

11. - E2D08

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

Select	Answer
A	Connect
B	Disconnect
C	Acknowledgement
D	Unnumbered Information

12. - E2E05

Which of these digital modes does not support keyboard-to-keyboard operation?

Select	Answer
A	RTTY
B	PACTOR
C	MFSK
D	PSK31

13. - E3A14

What is meant by circularly polarized electromagnetic waves?

Select	Answer
A	Waves that circle the Earth
B	Waves with an electric field bent into a circular shape
C	Waves produced by a loop antenna
D	Waves with a rotating electric field

14. - E3B04

What is meant by the terms "extraordinary" and "ordinary" waves?

Select	Answer
A	Refracted rays and reflected waves
B	Long-path and short-path waves
C	Extraordinary waves describe rare long-skip propagation compared to ordinary waves, which travel shorter distances
D	Independent waves created in the ionosphere that are elliptically polarized

15. - E3C12

How does the maximum range of ground-wave propagation change when the signal frequency is increased?

Select	Answer
A	It stays the same
B	It decreases
C	It peaks at roughly 14 MHz
D	It increases

16. - E4A05

What is the purpose of the prescaler function on a frequency counter?

Select	Answer
A	It multiplies a higher frequency signal so a low-frequency counter can display the operating frequency
B	It divides a higher frequency signal so a low-frequency counter can display the input frequency
C	It amplifies low-level signals for more accurate counting
D	It prevents oscillation in a low-frequency counter circuit

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

18. - E4C04

What is the noise figure of a receiver?

Select	Answer
A	The ratio of thermal noise to atmospheric noise
B	The ratio of the noise bandwidth in hertz to the theoretical bandwidth of a resistive network
C	The ratio in dB of the noise generated by the receiver to the theoretical minimum noise
D	The ratio of atmospheric noise to phase 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	Cross-modulation interference
C	Squelch gain rollback
D	Desensitization

20. - E4E06

What is one type of electrical interference that might be caused by a nearby personal computer?

Select	Answer
A	A loud AC hum in the audio output of your station receiver
B	A clicking noise at intervals of a few seconds
C	A whining type noise that continually pulses off and on
D	The appearance of unstable modulated or unmodulated signals at specific frequencies

21. - E5A12

What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 3.7 MHz and a Q of 118?

Select	Answer
A	436.6 kHz
B	15.7 kHz
C	31.4 kHz
D	218.3 kHz

22. - E5B03

How is impedance in polar form converted to an equivalent admittance?

Select	Answer
A	Take the square root of the magnitude and add 180 degrees to the angle
B	Square the magnitude and subtract 90 degrees from the angle
C	Take the reciprocal of the angle and change the sign of the magnitude
D	Take the reciprocal of the magnitude and change the sign of the angle

23. - E5C02

How are impedances described in polar coordinates?

Select	Answer
A	By Y and G values
B	By phase angle and magnitude
C	By X and R values
D	By real and imaginary parts

24. - E5D04

Why are short connections used at microwave frequencies?

Select	Answer
A	To increase neutralizing resistance
B	To reduce phase shift along the connection
C	To reduce noise figure
D	To increase compensating capacitance

25. - E6A02

Which of the following semiconductor materials contains excess free electrons?

Select	Answer
A	Insulated gate
B	Bipolar
C	P-type
D	N-type

26. - E6B01

What is the most useful characteristic of a Zener diode?

Select	Answer
A	A negative resistance region
B	A constant current drop under conditions of varying voltage
C	A constant voltage drop under conditions of varying current
D	An internal capacitance that varies with the applied voltage

27. - E6C04

Which of the following is an advantage of BiCMOS logic?

Select	Answer
A	Its simplicity results in much less expensive devices than standard CMOS
B	It has the high input impedance of CMOS and the low output impedance of bipolar transistors
C	It is immune to electrostatic damage
D	All these choices are correct

28. - E6D09

What devices are commonly used as VHF and UHF parasitic suppressors at the input and output terminals of a transistor HF amplifier?

Select	Answer
A	Butterworth filters
B	Electrolytic capacitors
C	Ferrite beads
D	Steel-core toroids

29. - E6E08

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

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

30. - E6F03

What is the most common configuration of an optoisolator or optocoupler?

Select	Answer
A	A frequency modulated helium-neon laser
B	An amplitude modulated helium-neon laser
C	A lens and a photomultiplier
D	An LED and a phototransistor

31. - E7A09

What logical operation is performed by an exclusive NOR gate?

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

32. - E7B18

What is a characteristic of a grounded-grid amplifier?

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

33. - E7C12

What is one advantage of a Pi-matching network over an L-matching network consisting of a single inductor and a single capacitor?

Select	Answer
A	Pi-networks provide balanced input and output
B	L-networks cannot perform impedance transformation
C	The Q of Pi-networks can be controlled
D	Pi-networks are more stable

34. - E7D07

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

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

35. - E7E05

What circuit is added to an FM transmitter to boost the higher audio frequencies?

Select	Answer
A	A heterodyne enhancer
B	A heterodyne suppressor
C	A de-emphasis network
D	A pre-emphasis network

36. - E7F03

What type of digital signal processing filter is used to generate an SSB signal?

Select	Answer
A	An adaptive filter
B	A Hilbert-transform filter
C	An elliptical filter
D	A notch filter

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	47
B	0.21
C	94
D	24

38. - E7H05

How is positive feedback supplied in a Pierce oscillator?

Select	Answer
A	Through a neutralizing capacitor
B	Through a tapped coil
C	Through link coupling
D	Through a quartz crystal

39. - E8A09

How many different input levels can be encoded by an analog-to-digital converter with 8-bit resolution?

Select	Answer
A	256
B	8 multiplied by the gain of the input amplifier
C	8
D	256 divided by the gain of the input amplifier

40. - E8B05

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus-or-minus 5 kHz when the maximum modulation frequency is 3 kHz?

Select	Answer
A	1.67
B	0.167
C	0.6
D	60

41. - E8C07

What is the bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?

Select	Answer
A	9.6 kHz
B	4.8 kHz
C	15.36 kHz
D	5.76 kHz

42. - E8D09

What is considered an acceptable maximum IMD level for an idling PSK signal?

Select	Answer
A	-20 dB
B	-30 dB
C	+15 dB
D	+10 dB

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	8.15 dB
B	6.0 dB
C	2.79 dB
D	3.85 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	Method of Moments
C	Mutual impedance analysis
D	Graphical analysis

45. - E9C14

How does the performance of a horizontally polarized antenna mounted on the side of a hill compare with the same antenna mounted on flat ground?

Select	Answer
A	The main lobe takeoff angle decreases in the downhill direction
B	The main lobe takeoff angle increases in the downhill direction
C	The horizontal beamwidth decreases in the downhill direction
D	The horizontal beamwidth increases in the uphill direction

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

47. - E9E10

Which of these choices is an effective way to match an antenna with a 100-ohm feed point impedance to a 50-ohm coaxial cable feed line?

Select	Answer
A	Connect a 1/4-wavelength open stub of 300-ohm twinlead in parallel with the coaxial feed line where it connects to the antenna
B	Insert a 1/4-wavelength piece of 75-ohm coaxial cable transmission line in series between the antenna terminals and the 50-ohm feed cable
C	Connect a 1/2 wavelength shorted stub of 75-ohm cable in parallel with the 50-ohm cable where it attaches to the antenna
D	Insert a 1/2 wavelength piece of 300-ohm twinlead in series between the antenna terminals and the 50-ohm feed cable

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	5.3 meters
B	4.3 meters
C	10.6 meters
D	3.5 meters

49. - E9G05

Which of the following is a common use for a Smith chart?

Select	Answer
A	Determine the impedance of a transmission line, given the physical dimensions
B	Determine the loss/100 feet of a transmission line, given the velocity factor and conductor materials
C	Determine the gain of an antenna given the physical and electrical parameters
D	Determine the length and position of an impedance matching stub

50. - E9H05

What is the main drawback of a small wire-loop antenna for direction finding?

Select	Answer
A	It has a bidirectional pattern
B	All these choices are correct
C	It is practical for use only on VHF and higher bands
D	It has no clearly defined null

Figure E7-2