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

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1. - E0A10

What toxic material may be present in some electronic components such as high voltage capacitors and transformers?

Select	Answer
A	Polymorphic silicon
B	Polytetrafluoroethylene
C	Polychlorinated biphenyls
D	Polyethylene

2. - E1A11

Which of the following describes authorization or licensing required when operating an amateur station aboard a U.S.-registered vessel in international waters?

Select	Answer
A	An unrestricted Radiotelephone Operator Permit
B	Any FCC-issued amateur license
C	Any amateur license with an FCC Marine or Aircraft endorsement
D	Only General Class or higher amateur licenses

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

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	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	The U.S. embassy must approve of your operation

5. - E1D08

Which VHF amateur bands have frequencies authorized for space stations?

Select	Answer
A	6 meters and 2 meters
B	2 meters and 1.25 meters
C	2 meters
D	6 meters, 2 meters, and 1.25 meters

6. - E1E05

What is the minimum passing score on all amateur operator license examinations?

Select	Answer
A	Minimum passing score of 77%
B	Minimum passing score of 70%
C	Minimum passing score of 80%
D	Minimum passing score of 74%

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	All privileges of the Amateur Extra Class 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	None, they must obtain a U.S. license

8. - E2A04

What is meant by the term mode? as applied to an amateur radio satellite?

Select	Answer
A	The satellite's uplink and downlink frequency bands
B	The satellite's orientation with respect to the Earth
C	Whether the satellite is in a low earth or geostationary orbit
D	Whether the satellite is in a polar or equatorial orbit

9. - E2B10

What aspect of an analog slow-scan television signal encodes the brightness of the picture?

Select	Answer
A	Sync frequency
B	Sync amplitude
C	Tone frequency
D	Tone amplitude

10. - E2C01

What indicator is required to be used by U.S.-licensed operators when operating a station via remote control and the remote transmitter is located in the U.S.?

Select	Answer
A	/R# where # is the district of the remote station
B	/ followed by the USPS two-letter abbreviation for the state in which the remote station is located
C	/ followed by the ARRL Section of the remote station
D	No additional indicator is required

11. - E2D05

What is one advantage of the JT65 mode?

Select	Answer
A	The ability to decode signals which have a very low signal-to-noise ratio
B	Permits fast-scan TV transmissions over narrow bandwidth
C	Uses only a 65 Hz bandwidth
D	Easily copied by ear if necessary

12. - E2E09

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

Select	Answer
A	PACTOR
B	RTTY
C	MT63
D	PSK31

13. - E3A13

Which of these emission modes is best for auroral propagation?

Select	Answer
A	CW
B	FM
C	SSB
D	RTTY

14. - E3B02

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

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

15. - E3C07

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

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

16. - E4A04

How is the compensation of an oscilloscope probe typically adjusted?

Select	Answer
A	A square wave is displayed and the probe is adjusted until the horizontal portions of the displayed wave are as nearly flat as possible
B	A high frequency sine wave is displayed and the probe is adjusted for maximum amplitude
C	A frequency standard is displayed and the probe is adjusted until the deflection time is accurate
D	A DC voltage standard is displayed and the probe is adjusted until the displayed voltage is accurate

17. - E4B02

What is the significance of voltmeter sensitivity expressed in ohms per volt?

Select	Answer
A	The full scale reading of the voltmeter multiplied by its ohms per volt rating will indicate the input impedance of the voltmeter
B	When used as a galvanometer, the reading in volts multiplied by the ohms per volt rating will determine the power drawn by the device under test
C	When used as an ohmmeter, the reading in ohms divided by the ohms per volt rating will determine the voltage applied to the circuit
D	When used as an ammeter, the full scale reading in amps divided by ohms per volt rating will determine the size of shunt needed

18. - E4C06

A CW receiver with the AGC off has an equivalent input noise power density of -174 dBm/Hz. What would be the level of an unmodulated carrier input to this receiver that would yield an audio output SNR of 0 dB in a 400 Hz noise bandwidth?

Select	Answer
A	-164 dBm
B	-155 dBm
C	-174 dBm
D	-148 dBm

19. - E4D04

Which of the following may reduce or eliminate intermodulation interference in a repeater caused by another transmitter operating in close proximity?

Select	Answer
A	Utilizing a Class C final amplifier
B	Utilizing a Class D final amplifier
C	A properly terminated circulator at the output of the repeater's transmitter
D	A band-pass filter in the feed line between the transmitter and receiver

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	Removal of the CW signal as well as the interfering carrier
C	Ringing in the DSP filter will completely remove the spaces between the CW characters
D	Received CW signals will appear to be modulated at the DSP clock frequency

21. - E5A03

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

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

22. - E5B09

What is the relationship between the AC current through a capacitor and the voltage across a capacitor?

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

23. - E5C03

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

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

24. - E5D10

How can the true power be determined in an AC circuit where the voltage and current are out of phase?

Select	Answer
A	By multiplying the apparent power by the power factor
B	By dividing the apparent power by the power factor
C	By multiplying the reactive power by the power factor
D	By dividing the reactive power by the power factor

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

26. - E6B11

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

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

27. - E6C08

In Figure E6-3, what is the schematic symbol for a NAND gate?

Select	Answer
A	2
B	1
C	4
D	3

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

29. - E6E06

What characteristics of the MMIC make it a popular choice for VHF through microwave circuits?

Select	Answer
A	Plate current that is controlled by a control grid
B	Controlled gain, low noise figure, and constant input and output impedance over the specified frequency range
C	The ability to retrieve information from a single signal even in the presence of other strong signals
D	Nearly infinite gain, very high input impedance, and very low output impedance

30. - E6F11

What is the approximate open-circuit voltage produced by a fully illuminated silicon photovoltaic cell?

Select	Answer
A	0.1 V
B	12 V
C	0.5 V
D	1.5 V

31. - E7A06

What is a characteristic of a monostable multivibrator?

Select	Answer
A	It produces a continuous square wave oscillating between 1 and 0
B	It switches momentarily to the opposite binary state and then returns to its original state after a set time
C	It stores one bit of data in either a 0 or 1 state
D	It maintains a constant output voltage, regardless of variations in the input voltage

32. - E7B14

Why are switching amplifiers more efficient than linear amplifiers?

Select	Answer
A	Linear amplifiers have high gain resulting in higher harmonic content
B	Switching amplifiers operate at higher voltages
C	The power transistor is at saturation or cutoff most of the time
D	Switching amplifiers use push-pull circuits

33. - E7C08

Which of the following factors has the greatest effect on the bandwidth and response shape of a crystal ladder filter?

Select	Answer
A	The relative frequencies of the individual crystals
B	The amplitude of the signals passing through the filter
C	The DC voltage applied to the quartz crystal
D	The gain of the RF stage preceding the filter

34. - E7D01

How does a linear electronic voltage regulator work?

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

35. - E7E06

Why is de-emphasis commonly used in FM communications receivers?

Select	Answer
A	To reduce impulse noise reception
B	To remove third-order distortion products
C	For higher efficiency
D	For compatibility with transmitters using phase modulation

36. - E7F14

Which of the following would allow a digital signal processing filter to create a sharper filter response?

Select	Answer
A	More taps
B	Higher data rate
C	Complex phasor representations
D	Double-precision math routines

37. - E7G09

What will be the output voltage of the circuit shown in Figure E7-3 if R1 is 1000 ohms, RF is 10,000 ohms, and 0.23 volts DC is applied to the input?

Select	Answer
A	2.3 volts
B	-2.3 volts
C	-0.23 volts
D	0.23 volts

38. - E7H14

What is a phase-locked loop circuit?

Select	Answer
A	An electronic circuit also known as a monostable multivibrator
B	An electronic servo loop consisting of a phase detector, a low-pass filter, a voltage-controlled oscillator, and a stable reference oscillator
C	An electronic circuit consisting of a precision push-pull amplifier with a differential input
D	An electronic servo loop consisting of a ratio detector, reactance modulator, and voltage-controlled oscillator

39. - E8A09

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

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

40. - E8B07

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

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

41. - E8C05

What is the approximate bandwidth of a 13-WPM International Morse Code transmission?

Select	Answer
A	104 Hz
B	13 Hz
C	52 Hz
D	26 Hz

42. - E8D04

What is the primary effect of extremely short rise or fall time on a CW signal?

Select	Answer
A	The generation of key clicks
B	More difficult to copy
C	The generation of RF harmonics
D	Limits data speed

43. - E9A07

What is the effective isotropic radiated power of a repeater station with 200 watts transmitter power output, 2 dB feed line loss, 2.8 dB duplexer loss, 1.2 dB circulator loss, and 7 dBi antenna gain?

Select	Answer
A	252 watts
B	159 watts
C	632 watts
D	63.2 watts

44. - E9B06

What is the elevation angle of peak response in the antenna radiation pattern shown in Figure E9-2?

Select	Answer
A	75 degrees
B	7.5 degrees
C	25 degrees
D	45 degrees

45. - E9C04

What happens to the radiation pattern of an unterminated long wire antenna as the wire length is increased?

Select	Answer
A	The vertical angle increases
B	The front-to-back ratio decreases
C	The lobes align more in the direction of the wire
D	The lobes become more perpendicular to the wire

46. - E9D07

What is an advantage of using top loading in a shortened HF vertical antenna?

Select	Answer
A	Higher losses
B	Improved radiation efficiency
C	Greater structural strength
D	Lower Q

47. - E9E03

What is the name of the matching system that uses a section of transmission line connected in parallel with the feed line at or near the feed point?

Select	Answer
A	The omega match
B	The stub match
C	The gamma match
D	The delta match

48. - E9F02

Which of the following has the biggest effect on the velocity factor of a transmission line?

Select	Answer
A	The termination impedance
B	The center conductor resistivity
C	The line length
D	Dielectric materials used in the line

49. - E9G08

What is the process of normalization with regard to a Smith chart?

Select	Answer
A	Reassigning resistance values with regard to the reactance axis
B	Reassigning reactance values with regard to the resistance axis
C	Reassigning impedance values with regard to the prime center
D	Reassigning prime center with regard to the reactance axis

50. - E9H08

What is the function of a sense antenna?

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

Figure E6-3

Figure E7-3

Figure E9-2