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

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

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 form FSD-15 must be submitted to the Department of the Interior
C	A proposal must be submitted to the National Park Service
D	A letter of intent must be filed with the Environmental Protection Agency

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

5. - E1D05

What must be posted at the station location of a station being operated by telecommand on or within 50 km of the earth's surface?

Select	Answer
A	A photocopy of the station license
B	A label with the name, address, and telephone number of the station licensee
C	All these choices are correct
D	A label with the name, address, and telephone number of the control operator

6. - E1E10

What must the administering VEs do after the administration of a successful examination for an amateur operator license?

Select	Answer
A	They must collect and submit the documents to the coordinating VEC for grading
B	They must submit the application document to the coordinating VEC according to the coordinating VEC instructions
C	They must collect and send the documents to the FCC according to instructions
D	They must collect and send the documents to the NCVEC for grading

7. - E1F02

What privileges are authorized in the U.S. to persons holding an amateur service license granted by the government of Canada?

Select	Answer
A	None, they must obtain a U.S. license
B	Full privileges, up to and including those of the Amateur Extra Class license, on the 80, 40, 20, 15, and 10 meter bands
C	The operating terms and conditions of the Canadian amateur service license, not to exceed U.S. Amateur Extra Class license privileges
D	All privileges of the Amateur Extra Class license

8. - E2A05

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

Select	Answer
A	The location of the ground control station
B	The uplink and downlink frequency ranges
C	Power limits for uplink and downlink transmissions
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	60
B	120
C	30
D	90

10. - E2C12

What technique do individual nodes use to form a mesh network?

Select	Answer
A	Acting as store-and-forward digipeaters
B	Discovery and link establishment protocols
C	Forward error correction and Viterbi codes
D	Custom code plugs for the local trunking systems

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. - E2E09

Which of the following HF digital modes uses variable-length coding for bandwidth efficiency?

Select	Answer
A	PACTOR
B	PSK31
C	RTTY
D	MT63

13. - E3A04

What do Hepburn maps predict?

Select	Answer
A	Probability of tropospheric propagation
B	Locations of auroral reflecting zones
C	Sporadic E propagation
D	Likelihood of rain scatter along cold or warm fronts

14. - E3B09

At what time of year is sporadic E propagation most likely to occur?

Select	Answer
A	Around the solstices, especially the winter solstice
B	Around the equinoxes, especially the spring equinox
C	Around the solstices, especially the summer solstice
D	Around the equinoxes, especially the fall equinox

15. - E3C02

What is indicated by a rising A or K index?

Select	Answer
A	Increasing disruption of the geomagnetic field
B	Decreasing disruption of the geomagnetic field
C	An increase in the critical frequency
D	Higher levels of solar UV radiation

16. - E4A06

What is the effect of aliasing on a digital oscilloscope caused by setting the time base too slow?

Select	Answer
A	A false, jittery low-frequency version of the signal is displayed
B	Excessive blanking occurs, which prevents display of the signal
C	Calibration of the vertical scale is no longer valid
D	All signals will have a DC offset

17. - E4B05

What three test loads are used to calibrate an RF vector network analyzer?

Select	Answer
A	50 ohms, 75 ohms, and 90 ohms
B	Short circuit, open circuit, and 50 ohms
C	Short circuit, open circuit, and resonant circuit
D	50 ohms through 1/8 wavelength, 1/4 wavelength, and 1/2 wavelength of coaxial cable

18. - E4C04

What is the noise figure of a receiver?

Select	Answer
A	The ratio of the noise bandwidth in hertz to the theoretical bandwidth of a resistive network
B	The ratio in dB of the noise generated by the receiver to the theoretical minimum noise
C	The ratio of thermal noise to atmospheric noise
D	The ratio of atmospheric noise to phase noise

19. - E4D09

What is the purpose of the preselector in a communications receiver?

Select	Answer
A	To allow selection of the optimum RF amplifier device
B	To store often-used frequencies
C	To provide a range of AGC time constants
D	To increase rejection of signals outside the desired band

20. - E4E01

What problem can occur when using an automatic notch filter (ANF) to remove interfering carriers while receiving CW signals?

Select	Answer
A	Any nearby signal passing through the DSP system will overwhelm the desired signal
B	Ringing in the DSP filter will completely remove the spaces between the CW characters
C	Removal of the CW signal as well as the interfering carrier
D	Received CW signals will appear to be modulated at the DSP clock frequency

21. - E5A10

How is the Q of an RLC series resonant circuit calculated?

Select	Answer
A	Resistance divided by the reactance of either the inductance or capacitance
B	Reactance of either the inductance or capacitance multiplied by the resistance
C	Reactance of the inductance multiplied by the reactance of the capacitance
D	Reactance of either the inductance or capacitance divided by the resistance

22. - E5B12

What is admittance?

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

23. - E5C03

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

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

24. - E5D12

How many watts are consumed in a circuit having a power factor of 0.2 if the input is 100 VAC at 4 amperes?

Select	Answer
A	2000 watts
B	80 watts
C	400 watts
D	50 watts

25. - E6A05

How does DC input impedance at the gate of a field-effect transistor compare with the DC input impedance of a bipolar transistor?

Select	Answer
A	An FET has higher input impedance
B	They are both high impedance
C	They are both low impedance
D	An FET has lower input impedance

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. - E6C11

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

Select	Answer
A	4
B	2
C	6
D	5

28. - E6D08

What is one reason for using powdered-iron cores rather than ferrite cores in an inductor?

Select	Answer
A	Powdered-iron cores use smaller diameter wire for the same inductance
B	Powdered-iron cores generally have greater initial permeability
C	Powdered-iron cores generally require fewer turns to produce a given inductance
D	Powdered-iron cores generally maintain their characteristics at higher currents

29. - E6E08

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

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

30. - E6F03

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

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

31. - E7A08

What logical operation does an OR gate perform?

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

32. - E7B13

Which of the following describes an emitter follower (or common collector) amplifier?

Select	Answer
A	An OR circuit with only one emitter used for output
B	A two-transistor amplifier with the emitters sharing a common bias resistor
C	A differential amplifier with both inputs fed to the emitter of the input transistor
D	An amplifier with a low impedance output that follows the base input voltage

33. - E7C09

What is a crystal lattice filter?

Select	Answer
A	A filter with narrow bandwidth and steep skirts made using quartz crystals
B	A filter using lattice-shaped quartz crystals for high-Q performance
C	An audio filter made with four quartz crystals that resonate at 1 kHz intervals
D	A power supply filter made with interlaced quartz crystals

34. - E7D14

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

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

35. - E7E11

Which type of detector circuit is used for demodulating SSB signals?

Select	Answer
A	Product detector
B	Phase detector
C	Discriminator
D	Phase comparator

36. - E7F07

What function is performed by a Fast Fourier Transform?

Select	Answer
A	Converting digital signals from the time domain to the frequency domain
B	Converting digital signals to analog form
C	Converting 8-bit data to 16-bit data
D	Converting analog signals to digital form

37. - E7G08

How does the gain of an ideal operational amplifier vary with frequency?

Select	Answer
A	It increases linearly with increasing frequency
B	It decreases logarithmically with increasing frequency
C	It decreases linearly with increasing frequency
D	It does not vary with frequency

38. - E7H15

Which of these functions can be performed by a phase-locked loop?

Select	Answer
A	Photovoltaic conversion, optical coupling
B	Frequency synthesis, FM demodulation
C	Wide-band AF and RF power amplification
D	Comparison of two digital input signals, digital pulse counter

39. - E8A02

Which of the following is a type of analog-to-digital conversion?

Select	Answer
A	Successive approximation
B	Phase reversal
C	Level shifting
D	Harmonic regeneration

40. - E8B09

What is deviation ratio?

Select	Answer
A	The ratio of the carrier center frequency to the audio modulating frequency
B	The ratio of the audio modulating frequency to the center carrier frequency
C	The ratio of the highest audio modulating frequency to the average audio modulating frequency
D	The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency

41. - E8C06

What is the bandwidth of a 170-hertz shift, 300-baud ASCII transmission?

Select	Answer
A	1.0 kHz
B	0.3 kHz
C	0.5 kHz
D	0.1 Hz

42. - E8D01

Why are received spread spectrum signals resistant to interference?

Select	Answer
A	If interference is detected by the receiver it will signal the transmitter to change frequencies
B	The receiver is always equipped with a digital blanker
C	Signals not using the spread spectrum algorithm are suppressed in the receiver
D	The high power used by a spread spectrum transmitter keeps its signal from being easily overpowered

43. - E9A11

Which of the following factors determines ground losses for a ground-mounted vertical antenna operating in the 3 MHz to 30 MHz range?

Select	Answer
A	The standing wave ratio
B	Distance from the transmitter
C	Soil conductivity
D	Take-off angle

44. - E9B04

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

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

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	Omni-directional
C	Cardioid
D	A figure-8 oriented along the axis of the array

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 lower the radiation angle
D	To minimize the Q

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 omega matching system
B	The delta matching system
C	The gamma matching system
D	The stub 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	7.0 meters
B	8.5 meters
C	10.6 meters
D	13.3 meters

49. - E9G04

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

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

50. - E9H08

What is the function of a sense antenna?

Select	Answer
A	It allows DF antennas to receive signals at different vertical angles
B	It increases the sensitivity of a DF antenna array
C	It provides diversity reception that cancels multipath signals
D	It modifies the pattern of a DF antenna array to provide a null in one direction

Figure E6-3