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

Logging in (or registering) will help the system to select questions that you need to focus on.

1. - E0A07

How may dangerous levels of carbon monoxide from an emergency generator be detected?

Select	Answer
A	By the yellowish appearance of the gas
B	Only with a carbon monoxide detector
C	By the odor
D	Any ordinary smoke detector can be used

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

3. - E1B11

What does PRB-1 require of regulations affecting amateur radio?

Select	Answer
A	Amateur radio operations must be permitted in any private residence
B	Reasonable accommodations of amateur radio must be made
C	No limitations may be placed on antenna size or placement
D	Use of wireless devices in a vehicle is exempt from regulation

4. - E1C10

What is the permitted mean power of any spurious emission relative to the mean power of the fundamental emission from a station transmitter or external RF amplifier installed after January 1, 2003 and transmitting on a frequency below 30 MHz?

Select	Answer
A	At least 73 dB below
B	At least 53 dB below
C	At least 63 dB below
D	At least 43 dB below

5. - E1D12

Which of the following amateur stations may transmit one-way communications?

Select	Answer
A	A local repeater or linked repeater station
B	A message forwarding station or automatically controlled digital station
C	All these choices are correct
D	A space station, beacon station, or telecommand station

6. - E1E03

What is a Volunteer Examiner Coordinator?

Select	Answer
A	An organization that has entered into an agreement with the FCC to coordinate, prepare, and administer amateur operator license examinations
B	The person who has entered into an agreement with the FCC to be the VE session manager
C	A person who has volunteered to administer amateur operator license examinations
D	A person who has volunteered to prepare amateur operator license examinations

7. - E1F04

Which of the following geographic descriptions approximately describes "Line A"?

Select	Answer
A	A line roughly parallel to and west of the U.S. Atlantic coastline
B	A line roughly parallel to and north of the border between the U.S. and Mexico
C	A line roughly parallel to and east of the U.S. Pacific coastline
D	A line roughly parallel to and south of the border between the U.S. and Canada

8. - E2A12

What is the purpose of digital store-and-forward functions on an amateur radio satellite?

Select	Answer
A	To upload operational software for the transponder
B	To delay download of telemetry between satellites
C	To store digital messages in the satellite for later download by other stations
D	To relay messages between satellites

9. - E2B11

What is the function of the Vertical Interval Signaling (VIS) code sent as part of an SSTV transmission?

Select	Answer
A	To provide vertical synchronization
B	To identify the call sign of the station transmitting
C	To identify the SSTV mode being used
D	To lock the color burst oscillator in color SSTV images

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	No additional indicator is required
D	/ followed by the ARRL Section of the remote station

11. - E2D01

Which of the following digital modes is designed for meteor scatter communications?

Select	Answer
A	APRS
B	MSK144
C	Hellschreiber
D	WSPR

12. - E2E09

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

Select	Answer
A	PSK31
B	RTTY
C	PACTOR
D	MT63

13. - E3A11

What is a typical range for tropospheric propagation of microwave signals?

Select	Answer
A	1200 miles
B	2500 miles
C	100 miles to 300 miles
D	10 miles to 50 miles

14. - E3B04

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

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

15. - E3C03

Which of the following signal paths is most likely to experience high levels of absorption when the A index or K index is elevated?

Select	Answer
A	Transequatorial
B	Polar
C	NVIS
D	Sporadic E

16. - E4A02

Which of the following parameters does a spectrum analyzer display on the vertical and horizontal axes?

Select	Answer
A	RF amplitude and time
B	SWR and frequency
C	RF amplitude and frequency
D	SWR and time

17. - E4B01

Which of the following factors most affects the accuracy of a frequency counter?

Select	Answer
A	Time base accuracy
B	Input attenuator accuracy
C	Decade divider accuracy
D	Temperature coefficient of the logic

18. - E4C13

How does a narrow-band roofing filter affect receiver performance?

Select	Answer
A	All these choices are correct
B	It improves intelligibility by using low Q circuitry to reduce ringing
C	It improves dynamic range by attenuating strong signals near the receive frequency
D	It improves sensitivity by reducing front end noise

19. - E4D10

What does a third-order intercept level of 40 dBm mean with respect to receiver performance?

Select	Answer
A	Signals less than 40 dBm will not generate audible third-order intermodulation products
B	A pair of 1 mW input signals will produce a third-order intermodulation product that is 40 dB stronger than the input signal
C	A pair of 40 dBm input signals will theoretically generate a third-order intermodulation product that has the same output amplitude as either of the input signals
D	The receiver can tolerate signals up to 40 dB above the noise floor without producing third-order intermodulation products

20. - E4E10

What might be the cause of a loud roaring or buzzing AC line interference that comes and goes at intervals?

Select	Answer
A	Arcing contacts in a thermostatically controlled device
B	All these choices are correct
C	A malfunctioning illuminated advertising display
D	A defective doorbell or doorbell transformer inside a nearby residence

21. - E5A09

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

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

22. - E5B03

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

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

23. - E5C08

What coordinate system is often used to display the phase angle of a circuit containing resistance, inductive and/or capacitive reactance?

Select	Answer
A	Polar coordinates
B	Elliptical coordinates
C	Faraday grid
D	Maidenhead grid

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	400 watts
B	80 watts
C	2000 watts
D	50 watts

25. - E6A07

Which of the following indicates that a silicon NPN junction transistor is biased on?

Select	Answer
A	Base-to-emitter voltage of approximately 6 to 7 volts
B	Base-to-emitter resistance of approximately 0.6 to 0.7 ohms
C	Base-to-emitter resistance of approximately 6 to 7 ohms
D	Base-to-emitter voltage of approximately 0.6 to 0.7 volts

26. - E6B04

What type of semiconductor device is designed for use as a voltage-controlled capacitor?

Select	Answer
A	Varactor diode
B	Zener diode
C	Tunnel diode
D	Silicon-controlled rectifier

27. - E6C03

What is tri-state logic?

Select	Answer
A	Low-power logic devices designed to operate at 3 volts
B	Logic devices with 0, 1, and high-impedance output states
C	Logic devices that utilize ternary math
D	Proprietary logic devices manufactured by Tri-State Devices

28. - E6D13

What is the primary cause of inductor self-resonance?

Select	Answer
A	Inter-turn capacitance
B	The skin effect
C	Non-linear core hysteresis
D	Inductive kickback

29. - E6E06

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

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

30. - E6F10

What is the most common type of photovoltaic cell used for electrical power generation?

Select	Answer
A	Silicon
B	Cadmium Sulfide
C	Copper oxide
D	Selenium

31. - E7A04

How many flip-flops are required to divide a signal frequency by 4?

Select	Answer
A	8
B	2
C	1
D	4

32. - E7B07

Which of the following is a likely result when a Class C amplifier is used to amplify a single-sideband phone signal?

Select	Answer
A	Increased overall intelligibility
B	Signal distortion and excessive bandwidth
C	Signal inversion
D	Reduced intermodulation products

33. - E7C03

What advantage does a series-L Pi-L-network have over a series-L Pi-network for impedance matching between the final amplifier of a vacuum-tube transmitter and an antenna?

Select	Answer
A	Greater transformation range
B	Does not require a capacitor
C	Greater harmonic suppression
D	Higher efficiency

34. - E7D06

What is the purpose of Q1 in the circuit shown in Figure E7-2?

Select	Answer
A	It provides negative feedback to improve regulation
B	It controls the current supplied to the load
C	It provides a constant load for the voltage source
D	It provides D1 with current

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 reactance modulator on the final amplifier
C	A balanced modulator on the oscillator
D	A reactance modulator on the oscillator

36. - E7F12

Which of the following is an advantage of a Finite Impulse Response (FIR) filter vs an Infinite Impulse Response (IIR) digital filter?

Select	Answer
A	FIR filters can delay all frequency components of the signal by the same amount
B	FIR filters are easier to implement for a given set of passband rolloff requirements
C	All these choices are correct
D	FIR filters can respond faster to impulses

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	-0.23 volts
B	0.23 volts
C	-2.3 volts
D	2.3 volts

38. - E7H09

What type of frequency synthesizer circuit uses a phase accumulator, lookup table, digital to analog converter, and a low-pass anti-alias filter?

Select	Answer
A	A diode-switching matrix synthesizer
B	A phase-locked loop synthesizer
C	A hybrid synthesizer
D	A direct digital synthesizer

39. - E8A02

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

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

40. - E8B01

What is the modulation index of an FM signal?

Select	Answer
A	The bandwidth of the transmitted signal divided by the modulating signal frequency
B	The ratio of frequency deviation to modulating signal frequency
C	The type of modulation used by the transmitter
D	The ratio of modulating signal amplitude to frequency deviation

41. - E8C10

How may data rate be increased without increasing bandwidth?

Select	Answer
A	Using forward error correction
B	Increasing analog-to-digital conversion resolution
C	It is impossible
D	Using a more efficient digital code

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 is possible to transmit both upper and lower case text
C	It includes built-in error correction features
D	It contains fewer information bits per character than any other code

43. - E9A09

What is antenna efficiency?

Select	Answer
A	Radiation resistance divided by total resistance
B	Total resistance divided by radiation resistance
C	Effective radiated power divided by transmitter output
D	Radiation resistance divided by transmission resistance

44. - E9B02

In the antenna radiation pattern shown in Figure E9-1, what is the front-to-back ratio?

Select	Answer
A	14 dB
B	24 dB
C	18 dB
D	36 dB

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 increases in the uphill direction
D	The horizontal beamwidth decreases in the downhill direction

46. - E9D02

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

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

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

49. - E9G04

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

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

50. - E9H07

Why is RF attenuation used when direction-finding?

Select	Answer
A	To narrow the receiver bandwidth
B	To prevent receiver overload which reduces pattern nulls
C	To compensate for isotropic directivity and the antenna effect of feed lines
D	To increase receiver sensitivity

Figure E7-2

Figure E7-3

Figure E9-1