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 to 3000 MHz
C	300 kHz to 3 MHz
D	30 to 300 MHz

2. - E1A08

If a station in a message forwarding system inadvertently forwards a message that is in violation of FCC rules, who is primarily accountable for the rules violation?

Select	Answer
A	The control operator of the packet bulletin board station
B	The control operators of all the stations in the system not authenticating the source from which they accept communications
C	The control operators of all the stations in the system
D	The control operator of the originating station

3. - E1B07

To what type of regulations does PRB-1 apply?

Select	Answer
A	Use of wireless devices in vehicles
B	Homeowners associations
C	FAA tower height limits
D	State and local zoning

4. - E1C14

How long must an operator wait after filing a notification with the Utilities Technology Council (UTC) before operating on the 2200 meter or 630 meter band?

Select	Answer
A	Operations may commence immediately, and may continue unless interference is reported by the UTC
B	Operators may operate after 30 days, providing they have not been told that their station is within 1 km of PLC systems using those frequencies
C	Operators may not operate until a test signal has been transmitted in coordination with the local power company
D	Operators must not operate until approval is received

5. - E1D03

What is a space telecommand station?

Select	Answer
A	An amateur station located in a satellite or a balloon more than 50 kilometers above the surface of the Earth
B	An amateur station that transmits communications to initiate, modify or terminate functions of a space station
C	An amateur station located on the surface of the Earth for communication with other Earth stations by means of Earth satellites
D	An amateur station that receives telemetry from a satellite or balloon more than 50 kilometers above the surface of the Earth

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

7. - E1F03

Under what circumstances may a dealer sell an external RF power amplifier capable of operation below 144 MHz if it has not been granted FCC certification?

Select	Answer
A	It was imported from a manufacturer in another country and was certificated by that country's government
B	It was imported from a manufacturer in a country that does not require certification of RF power amplifiers
C	The equipment dealer assembled it from a kit
D	It was purchased in used condition from an amateur operator and is sold to another amateur operator for use at that operator's station

8. - E2A07

Which of the following types of signals can be relayed through a linear transponder?

Select	Answer
A	PSK and packet
B	FM and CW
C	SSB and SSTV
D	All these choices are correct

9. - E2B04

How is color information sent in analog SSTV?

Select	Answer
A	Color is sent in a color burst at the end of each line
B	Color information is sent on a 2.8 kHz subcarrier
C	Color is amplitude modulated on the frequency modulated intensity signal
D	Color lines are sent sequentially

10. - E2C09

What type of equipment is commonly used to implement an amateur radio mesh network?

Select	Answer
A	A 440 MHz transceiver with a 9600 baud modem
B	An optical cable connection between the USB ports of 2 separate computers
C	A wireless router running custom firmware
D	A 2 meter VHF transceiver with a 1200 baud modem

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	Easily copied by ear if necessary
C	Uses only a 65 Hz bandwidth
D	Permits fast-scan TV transmissions over narrow bandwidth

12. - E2E12

How do ALE stations establish contact?

Select	Answer
A	ALE constantly scans a list of frequencies, activating the radio when the designated call sign is received
B	ALE radios send a constant tone code to establish a frequency for future use
C	ALE radios activate when they hear their signal echoed by back scatter
D	ALE radios monitor an internet site for the frequency they are being paged on

13. - E3A09

Which of the following frequency ranges is most suited for meteor scatter communications?

Select	Answer
A	10 MHz - 14 MHz
B	28 MHz - 148 MHz
C	220 MHz - 450 MHz
D	1.8 MHz - 1.9 MHz

14. - E3B09

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

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

15. - E3C05

What orientation of Bz (B sub z) increases the likelihood that incoming particles from the sun will cause disturbed conditions?

Select	Answer
A	Eastward
B	Northward
C	Southward
D	Westward

16. - E4A04

How is the compensation of an oscilloscope probe typically adjusted?

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

17. - E4B04

Which S parameter represents input port return loss or reflection coefficient (equivalent to VSWR)?

Select	Answer
A	S22
B	S12
C	S11
D	S21

18. - E4C07

What does the MDS of a receiver represent?

Select	Answer
A	The maximum detectable spectrum
B	The multiplex distortion stability
C	The meter display sensitivity
D	The minimum discernible signal

19. - E4D01

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

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

20. - E4E08

What current flows equally on all conductors of an unshielded multi-conductor cable?

Select	Answer
A	Differential-mode current
B	Return current
C	Common-mode current
D	Reactive current only

21. - E5A09

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

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

22. - E5B08

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 100 ohms, R is 100 ohms, and XL is 75 ohms?

Select	Answer
A	76 degrees with the voltage lagging the current
B	14 degrees with the voltage lagging the current
C	76 degrees with the voltage leading the current
D	14 degrees with the voltage leading the current

23. - E5C02

How are impedances described in polar coordinates?

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

24. - E5D03

What is microstrip?

Select	Answer
A	Miniature coax used for low power applications
B	Precision printed circuit conductors above a ground plane that provide constant impedance interconnects at microwave frequencies
C	Short lengths of coax mounted on printed circuit boards to minimize time delay between microwave circuits
D	Lightweight transmission line made of common zip cord

25. - E6A08

What term indicates the frequency at which the grounded-base current gain of a transistor has decreased to 0.7 of the gain obtainable at 1 kHz?

Select	Answer
A	Corner frequency
B	Alpha cutoff frequency
C	Beta cutoff frequency
D	Alpha rejection frequency

26. - E6B05

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

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

27. - E6C10

In Figure E6-3, what is the schematic symbol for a NOR gate?

Select	Answer
A	3
B	4
C	1
D	2

28. - E6D05

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

Select	Answer
A	Ferrite toroids generally have lower initial permeability
B	Ferrite toroids generally have better temperature stability
C	Ferrite toroids generally require fewer turns to produce a given inductance value
D	Ferrite toroids are easier to use with surface mount technology

29. - E6E10

What advantage does surface-mount technology offer at RF compared to using through-hole components?

Select	Answer
A	All these choices are correct
B	Components have less parasitic inductance and capacitance
C	Smaller circuit area
D	Shorter circuit-board traces

30. - E6F06

Which of these materials is most commonly used to create photoconductive devices?

Select	Answer
A	A crystalline semiconductor
B	A liquid semiconductor
C	An ordinary metal
D	A heavy metal

31. - E7A11

What type of logic defines "1" as a high voltage?

Select	Answer
A	Assertive Logic
B	Negative logic
C	Positive Logic
D	Reverse Logic

32. - E7B18

What is a characteristic of a grounded-grid amplifier?

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

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

34. - E7D13

What is the equation for calculating power dissipated by a series linear voltage regulator?

Select	Answer
A	Input voltage divided by output current
B	Output voltage multiplied by output current
C	Voltage difference from input to output multiplied by output current
D	Input voltage multiplied by input current

35. - E7E01

Which of the following can be used to generate FM phone emissions?

Select	Answer
A	A balanced modulator on the oscillator
B	A reactance modulator on the final amplifier
C	A balanced modulator on the audio amplifier
D	A reactance modulator on the oscillator

36. - E7F06

What is the minimum number of bits required for an analog-to-digital converter to sample a signal with a range of 1 volt at a resolution of 1 millivolt?

Select	Answer
A	6 bits
B	4 bits
C	10 bits
D	8 bits

37. - E7G04

What is meant by the "op-amp input offset voltage"?

Select	Answer
A	The potential between the amplifier input terminals of the op-amp in an open loop condition
B	The differential input voltage needed to bring the open loop output voltage to zero
C	The difference between the output voltage of the op-amp and the input voltage required in the immediately following stage
D	The output voltage of the op-amp minus its input voltage

38. - E7H04

How is positive feedback supplied in a Colpitts oscillator?

Select	Answer
A	Through link coupling
B	Through a capacitive divider
C	Through a tapped coil
D	Through a neutralizing capacitor

39. - E8A02

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

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

40. - E8B07

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

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

41. - E8C06

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

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

42. - E8D09

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

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

43. - E9A01

What is an isotropic antenna?

Select	Answer
A	A spacecraft antenna used to direct signals toward Earth
B	A theoretical, omnidirectional antenna used as a reference for antenna gain
C	A grounded antenna used to measure Earth conductivity
D	A horizontally polarized antenna used to compare Yagi antennas

44. - E9B04

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

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

45. - E9C08

What is a folded dipole antenna?

Select	Answer
A	A dipole one-quarter wavelength long
B	A type of ground-plane antenna
C	A half-wave dipole with an additional parallel wire connecting its two ends
D	A dipole configured to provide forward gain

46. - E9D12

Which of the following would provide the best RF ground for your station?

Select	Answer
A	An electrically short connection to a metal water pipe
B	A 50-ohm resistor connected to ground
C	An electrically short connection to 3 or 4 interconnected ground rods via a series RF choke
D	An electrically short connection to 3 or 4 interconnected ground rods driven into the Earth

47. - E9E02

What is the name of an antenna matching system that matches an unbalanced feed line to an antenna by feeding the driven element both at the center of the element and at a fraction of a wavelength to one side of center?

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

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	8.5 meters
B	7.0 meters
C	10.6 meters
D	13.3 meters

49. - E9G03

Which of the following is often determined using a Smith chart?

Select	Answer
A	Satellite azimuth and elevation bearings
B	Beam headings and radiation patterns
C	Trigonometric functions
D	Impedance and SWR values in transmission lines

50. - E9H01

When constructing a Beverage antenna, which of the following factors should be included in the design to achieve good performance at the desired frequency?

Select	Answer
A	Its overall length must not exceed 1/4 wavelength
B	It should be configured as a four-sided loop
C	It must be mounted more than 1 wavelength above ground
D	It should be one or more wavelengths long

Figure E6-3