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. - E0A06

Why are there separate electric (E) and magnetic (H) field MPE limits?

Select	Answer
A	Ground reflections and scattering make the field strength vary with location
B	The body reacts to electromagnetic radiation from both the E and H fields
C	All these choices are correct
D	E field and H field radiation intensity peaks can occur at different locations

2. - E1A01

Which of the following carrier frequencies is illegal for LSB AFSK emissions on the 17 meter band RTTY and data segment of 18.068 to 18.110 MHz?

Select	Answer
A	18.068 MHz
B	18.100 MHz
C	18.107 MHz
D	18.110 MHz

3. - E1B09

Which amateur stations may be operated under RACES rules?

Select	Answer
A	Any FCC-licensed amateur station except a Technician Class
B	Only those club stations licensed to Amateur Extra Class operators
C	Any FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)
D	Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served

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	Operators may not operate until a test signal has been transmitted in coordination with the local power company
B	Operators must not operate until approval is received
C	Operations may commence immediately, and may continue unless interference is reported by the UTC
D	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

5. - E1D03

What is a space telecommand station?

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

6. - E1E04

Which of the following best describes the Volunteer Examiner accreditation process?

Select	Answer
A	The amateur operator applying must pass a VE examination administered by the FCC Enforcement Bureau
B	Each General, Advanced and Amateur Extra Class operator is automatically accredited as a VE when the license is granted
C	The procedure by which a VEC confirms that the VE applicant meets FCC requirements to serve as an examiner
D	The prospective VE obtains accreditation from the FCC

7. - E1F08

Which of the following types of amateur station communications are prohibited?

Select	Answer
A	Communications in a language other than English
B	Communications that have religious content
C	Communications transmitted for hire or material compensation, except as otherwise provided in the rules
D	Communications that have political content, except as allowed by the Fairness Doctrine

8. - E2A12

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

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

9. - E2B09

What hardware, other than a receiver with SSB capability and a suitable computer, is needed to decode SSTV using Digital Radio Mondiale (DRM)?

Select	Answer
A	A special IF converter
B	No other hardware is needed
C	A special notch filter to remove synchronization pulses
D	A special front end limiter

10. - E2C11

How should you generally identify your station when attempting to contact a DX station during a contest or in a pileup?

Select	Answer
A	Send only the last two letters of your call sign until you make contact
B	Send the call sign of the DX station three times, the words this is,then your call sign three times
C	Send your full call sign and grid square
D	Send your full call sign once or twice

11. - E2D10

How can an APRS station be used to help support a public service communications activity?

Select	Answer
A	An APRS station with an emergency medical technician can automatically transmit medical data to the nearest hospital
B	All these choices are correct
C	APRS stations with General Personnel Scanners can automatically relay the participant numbers and time as they pass the check points
D	An APRS station with a Global Positioning System unit can automatically transmit information to show a mobile station's position during the event

12. - E2E01

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

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

13. - E3A11

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

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

14. - E3B07

What happens to linearly polarized radio waves that split into ordinary and extraordinary waves in the ionosphere?

Select	Answer
A	They become elliptically polarized
B	They become depolarized
C	They become phase locked
D	They are bent toward the magnetic poles

15. - E3C06

By how much does the VHF/UHF radio horizon distance exceed the geometric horizon?

Select	Answer
A	By approximately twice the distance
B	By approximately four times the distance
C	By approximately 50 percent of the distance
D	By approximately 15 percent of the distance

16. - E4A05

What is the purpose of the prescaler function on a frequency counter?

Select	Answer
A	It divides a higher frequency signal so a low-frequency counter can display the input frequency
B	It amplifies low-level signals for more accurate counting
C	It multiplies a higher frequency signal so a low-frequency counter can display the operating frequency
D	It prevents oscillation in a low-frequency counter circuit

17. - E4B03

Which S parameter is equivalent to forward gain?

Select	Answer
A	S22
B	S21
C	S11
D	S12

18. - E4C09

Which of the following choices is a good reason for selecting a high frequency for the design of the IF in a superheterodyne HF or VHF communications receiver?

Select	Answer
A	Improved receiver noise figure
B	Easier for front-end circuitry to eliminate image responses
C	Fewer components in the receiver
D	Reduced drift

19. - E4D06

What is the term for spurious signals generated by the combination of two or more signals in a non-linear device or circuit?

Select	Answer
A	Neutralization
B	Amplifier desensitization
C	Adjacent channel interference
D	Intermodulation

20. - E4E07

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

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

21. - E5A15

Which of the following increases Q for inductors and capacitors?

Select	Answer
A	Lower losses
B	Lower reactance
C	Lower self-resonant frequency
D	Higher self-resonant frequency

22. - E5B06

What is susceptance?

Select	Answer
A	A measure of the efficiency of a transformer
B	The magnetic impedance of a circuit
C	The imaginary part of admittance
D	The ratio of magnetic field to electric field

23. - E5C01

Which of the following represents capacitive reactance in rectangular notation?

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

24. - E5D11

What is the power factor of an RL circuit having a 60-degree phase angle between the voltage and the current?

Select	Answer
A	1.73
B	1.414
C	0.866
D	0.5

25. - E6A09

What is a depletion-mode FET?

Select	Answer
A	An FET that exhibits a current flow between source and drain when no gate voltage is applied
B	Any FET without a channel
C	An FET that has no current flow between source and drain when no gate voltage is applied
D	Any FET for which holes are the majority carriers

26. - E6B01

What is the most useful characteristic of a Zener diode?

Select	Answer
A	A constant voltage drop under conditions of varying current
B	An internal capacitance that varies with the applied voltage
C	A negative resistance region
D	A constant current drop under conditions of varying voltage

27. - E6C02

What happens when the level of a comparator's input signal crosses the threshold?

Select	Answer
A	The comparator enters latch-up
B	The comparator changes its output state
C	The feedback loop becomes unstable
D	The IC input can be damaged

28. - E6D02

What is the equivalent circuit of a quartz crystal?

Select	Answer
A	Motional capacitance, motional inductance, and loss resistance in series, all in parallel with a shunt capacitor representing electrode and stray capacitance
B	Motional inductance and loss resistance in series, paralleled with motional capacitance and a capacitor representing electrode and stray capacitance
C	Motional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in series
D	Motional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in parallel

29. - E6E03

Which of the following materials is likely to provide the highest frequency of operation when used in MMICs?

Select	Answer
A	Silicon dioxide
B	Silicon nitride
C	Silicon
D	Gallium nitride

30. - E6F10

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

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

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 all inputs are logic 0
D	It produces logic 1 at its output if any or all inputs are logic 1

32. - E7B10

In Figure E7-1, what is the purpose of R1 and R2?

Select	Answer
A	Feedback
B	Voltage divider bias
C	Self bias
D	Load resistors

33. - E7C01

How are the capacitors and inductors of a low-pass filter Pi-network arranged between the network's input and output?

Select	Answer
A	A capacitor is connected between the input and ground, another capacitor is connected between the output and ground, and an inductor is connected between input and output
B	Two capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground
C	Two inductors are in series between the input and output, and a capacitor is connected between the two inductors and ground
D	An inductor is connected between the input and ground, another inductor is connected between the output and ground, and a capacitor is connected between the input and output

34. - E7D07

What is the purpose of C2 in the circuit shown in Figure E7-2?

Select	Answer
A	To provide fixed DC bias for Q1
B	To self-resonate at the hum frequency
C	It bypasses rectifier output ripple around D1
D	It is a brute force filter for the output

35. - E7E06

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

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

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	All these choices are correct
C	FIR filters are easier to implement for a given set of passband rolloff requirements
D	FIR filters can respond faster to impulses

37. - E7G04

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

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

38. - E7H07

How can an oscillator's microphonic responses be reduced?

Select	Answer
A	Reduce noise on the oscillator's power supply
B	Use NP0 capacitors
C	Increase the bias voltage
D	Mechanically isolate the oscillator circuitry from its enclosure

39. - E8A03

What type of wave does a Fourier analysis show to be made up of sine waves of a given fundamental frequency plus all its harmonics?

Select	Answer
A	A sine wave
B	A cosine wave
C	A sawtooth wave
D	A square wave

40. - E8B04

What is the modulation index of an FM-phone signal having a maximum carrier deviation of plus or minus 6 kHz when modulated with a 2 kHz modulating frequency?

Select	Answer
A	3
B	6000
C	1/3
D	2000

41. - E8C03

Why should phase-shifting of a PSK signal be done at the zero crossing of the RF signal?

Select	Answer
A	To simplify modulation
B	All these choices are correct
C	To improve carrier suppression
D	To minimize bandwidth

42. - E8D06

What is the advantage of including parity bits in ASCII characters?

Select	Answer
A	Faster transmission rate
B	Foreign language characters can be sent
C	The signal can overpower interfering signals
D	Some types of errors can be detected

43. - E9A01

What is an isotropic antenna?

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

44. - E9B05

What type of antenna pattern is shown in Figure E9-2?

Select	Answer
A	Radiation resistance
B	Elevation
C	Polarization
D	Azimuth

45. - E9C07

What is the approximate feed point impedance at the center of a two-wire folded dipole antenna?

Select	Answer
A	450 ohms
B	72 ohms
C	300 ohms
D	50 ohms

46. - E9D03

Where should a high Q loading coil be placed to minimize losses in a shortened vertical antenna?

Select	Answer
A	Near the center of the vertical radiator
B	At a voltage node
C	As low as possible on the vertical radiator
D	As close to the transmitter as possible

47. - E9E08

What is a use for a Wilkinson divider?

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

48. - E9F07

How does ladder line compare to small-diameter coaxial cable such as RG-58 at 50 MHz?

Select	Answer
A	Lower loss
B	Higher SWR
C	Smaller reflection coefficient
D	Lower velocity factor

49. - E9G11

How are the wavelength scales on a Smith chart calibrated?

Select	Answer
A	In fractions of transmission line electrical wavelength
B	In fractions of antenna electrical wavelength
C	In fractions of antenna electrical frequency
D	In fractions of transmission line electrical frequency

50. - E9H11

What feature of a cardioid pattern antenna makes it useful for direction finding?

Select	Answer
A	A very sharp peak
B	Broadband response
C	A very sharp single null
D	High radiation angle

Figure E7-1

Figure E7-2

Figure E9-2