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

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1. - E0A03

Over what range of frequencies are the FCC human body RF exposure limits most restrictive?

Select	Answer
A	3 to 30 MHz
B	300 kHz to 3 MHz
C	30 to 300 MHz
D	300 to 3000 MHz

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. - E1B11

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

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

4. - E1C13

What notifications must be given before transmitting on the 630 meter or 2200 meter bands?

Select	Answer
A	Operators must inform the Utilities Technology Council (UTC) of their call sign and coordinates of the station
B	An environmental impact statement must be filed with the Department of the Interior
C	Operators must inform the FAA of their intent to operate, giving their call sign and distance to the nearest runway
D	A special endorsement must be requested from the FCC

5. - E1D08

Which VHF amateur bands have frequencies authorized for space stations?

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

6. - E1E12

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

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

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

8. - E2A04

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

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

9. - E2B03

How is an interlaced scanning pattern generated in a fast-scan (NTSC) television system?

Select	Answer
A	By scanning two fields simultaneously
B	By scanning odd numbered lines in one field and even numbered lines in the next
C	By scanning lines from left to right in one field and right to left in the next
D	By scanning each field from bottom to top

10. - E2C12

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

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

11. - E2D09

What type of modulation is used for JT65 contacts?

Select	Answer
A	IEEE 802.11
B	PSK
C	RTTY
D	Multi-tone AFSK

12. - E2E01

Which of the following types of modulation is common for data emissions below 30 MHz?

Select	Answer
A	FSK
B	Spread spectrum
C	DTMF tones modulating an FM signal
D	Pulse modulation

13. - E3A12

What is the cause of auroral activity?

Select	Answer
A	An extreme low-pressure area in the polar regions
B	The interaction in the F2 layer between the solar wind and the Van Allen belt
C	Meteor showers concentrated in the extreme northern and southern latitudes
D	The interaction in the E layer of charged particles from the Sun with the Earth's magnetic field

14. - E3B09

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

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

15. - E3C02

What is indicated by a rising A or K index?

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

16. - E4A01

Which of the following limits the highest frequency signal that can be accurately displayed on a digital oscilloscope?

Select	Answer
A	Amount of memory
B	All these choices are correct
C	Q of the circuit
D	Sampling rate of the analog-to-digital converter

17. - E4B06

How much power is being absorbed by the load when a directional power meter connected between a transmitter and a terminating load reads 100 watts forward power and 25 watts reflected power?

Select	Answer
A	75 watts
B	100 watts
C	125 watts
D	25 watts

18. - E4C04

What is the noise figure of a receiver?

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

19. - E4D01

What is meant by the blocking dynamic range of a receiver?

Select	Answer
A	The difference in dB between the noise floor and the third-order intercept point
B	The difference in dB between the noise floor and the level of an incoming signal that will cause 1 dB of gain compression
C	The minimum difference in dB between two signals which produce third-order intermodulation products greater than the noise floor
D	The minimum difference in dB between the levels of two FM signals that will cause one signal to block the other

20. - E4E07

Which of the following can cause shielded cables to radiate or receive interference?

Select	Answer
A	Tying all ground connections to a common point resulting in differential-mode currents in the shield
B	Use of braided shielding material
C	Low inductance ground connections at both ends of the shield
D	Common-mode currents on the shield and conductors

21. - E5A05

What is the result of increasing the Q of an impedance-matching circuit?

Select	Answer
A	Matching range is increased
B	It has no effect on impedance matching
C	Matching bandwidth is decreased
D	Matching bandwidth is increased

22. - E5B04

What is the time constant of a circuit having two 220-microfarad capacitors and two 1-megohm resistors, all in parallel?

Select	Answer
A	440 seconds
B	220 seconds
C	110 seconds
D	55 seconds

23. - E5C01

Which of the following represents capacitive reactance in rectangular notation?

Select	Answer
A	+jX
B	Omega
C	-jX
D	Delta

24. - E5D01

What is the result of skin effect?

Select	Answer
A	Thermal effects on the surface of the conductor increase the impedance
B	As frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface
C	As frequency decreases, RF current flows in a thinner layer of the conductor, closer to the surface
D	Thermal effects on the surface of the conductor decrease the impedance

25. - E6A02

Which of the following semiconductor materials contains excess free electrons?

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

26. - E6B05

What characteristic of a PIN diode makes it useful as an RF switch?

Select	Answer
A	Low junction capacitance
B	Extremely high reverse breakdown voltage
C	Ability to dissipate large amounts of power
D	Reverse bias controls its forward voltage drop

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. - E6D04

Which materials are commonly used as a core in an inductor?

Select	Answer
A	Polystyrene and polyethylene
B	Ferrite and brass
C	Cobalt and aluminum
D	Teflon and Delrin

29. - E6E12

Why are DIP through-hole package ICs not typically used at UHF and higher frequencies?

Select	Answer
A	Epoxy coating is conductive above 300 MHz
B	Excessive lead length
C	Too many pins
D	Unsuitable for combining analog and digital signals

30. - E6F08

Why are optoisolators often used in conjunction with solid-state circuits when switching 120 VAC?

Select	Answer
A	Optoisolators eliminate the effects of reflected light in the control circuit
B	Optoisolators provide impedance matching between the control circuit and power circuit
C	Optoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched
D	Optoisolators provide a low impedance link between a control circuit and a power circuit

31. - E7A05

Which of the following is a circuit that continuously alternates between two states without an external clock?

Select	Answer
A	T flip-flop
B	J-K flip-flop
C	Astable multivibrator
D	Monostable multivibrator

32. - E7B01

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

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

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

34. - E7D05

Which of the following types of linear voltage regulator places a constant load on the unregulated voltage source?

Select	Answer
A	A constant current source
B	A shunt current source
C	A series regulator
D	A shunt regulator

35. - E7E05

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

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

36. - E7F08

What is the function of decimation?

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

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 does not vary with frequency
D	It decreases linearly with increasing frequency

38. - E7H12

Which of the following must be done to ensure that a crystal oscillator provides the frequency specified by the crystal manufacturer?

Select	Answer
A	Bias the crystal at a specified current
B	Provide the crystal with a specified parallel capacitance
C	Bias the crystal at a specified voltage
D	Provide the crystal with a specified parallel inductance

39. - E8A10

What is the purpose of a low-pass filter used in conjunction with a digital-to-analog converter?

Select	Answer
A	Improve accuracy by removing out-of-sequence codes from the input
B	Lower the input bandwidth to increase the effective resolution
C	Remove harmonics from the output caused by the discrete analog levels generated
D	All these choices are correct

40. - E8B02

How does the modulation index of a phase-modulated emission vary with RF carrier frequency?

Select	Answer
A	It does not depend on the RF carrier frequency
B	It increases as the RF carrier frequency increases
C	It decreases as the RF carrier frequency increases
D	It varies with the square root of the RF carrier frequency

41. - E8C02

What is the definition of symbol rate in a digital transmission?

Select	Answer
A	The number of characters carried per second by the station-to-station link
B	The duration of each bit in a message sent over the air
C	The rate at which the waveform changes to convey information
D	The number of control characters in a message packet

42. - E8D07

What is a common cause of overmodulation of AFSK signals?

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

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. - E9B08

What is the far field of an antenna?

Select	Answer
A	The region of the ionosphere where radiated power is not refracted
B	The region where the shape of the antenna pattern is independent of distance
C	The region where radiated power dissipates over a specified time period
D	The region where radiated field strengths are constant

45. - E9C13

How does the radiation pattern of a horizontally polarized 3-element beam antenna vary with increasing height above ground?

Select	Answer
A	The horizontal beamwidth increases
B	The horizontal beamwidth decreases
C	The takeoff angle of the lowest elevation lobe increases
D	The takeoff angle of the lowest elevation lobe decreases

46. - E9D09

What is the function of a loading coil used as part of an HF mobile antenna?

Select	Answer
A	To increase the SWR bandwidth
B	To lower the Q
C	To lower the losses
D	To cancel capacitive reactance

47. - E9E08

What is a use for a Wilkinson divider?

Select	Answer
A	It divides the operating frequency of a transmitter signal so it can be used on a lower frequency band
B	It is used to feed low-impedance loads from a high-impedance source
C	It is used to feed high-impedance antennas from a low-impedance source
D	It is used to divide power equally between two 50-ohm loads while maintaining 50-ohm input impedance

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 line length
C	Dielectric materials used in the line
D	The center conductor resistivity

49. - E9G04

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

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

50. - E9H04

What is an advantage of placing a grounded electrostatic shield around a small loop direction-finding antenna?

Select	Answer
A	It eliminates tracking errors caused by strong out-of-band signals
B	It adds capacitive loading, increasing the bandwidth of the antenna
C	It increases signal strength by providing a better match to the feed line
D	It eliminates unbalanced capacitive coupling to the surroundings, improving the nulls

Figure E6-3