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. - E0A01

What is the primary function of an external earth connection or ground rod?

Select	Answer
A	Lightning protection
B	Reduce RF current flow between pieces of equipment
C	Reduce received noise
D	Reduce RFI to telephones and home entertainment systems

2. - E1A14

Except in some parts of Alaska, what is the maximum power permitted on the 630 meter band?

Select	Answer
A	5 watts EIRP
B	100 watts PEP
C	1 watt EIRP
D	50 watts PEP

3. - E1B11

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

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

4. - E1C09

What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?

Select	Answer
A	0.5
B	2.0
C	3.0
D	1.0

5. - E1D06

What is the maximum permitted transmitter output power when operating a model craft by telecommand?

Select	Answer
A	1 watt
B	5 watts
C	2 watts
D	100 watts

6. - E1E08

To which of the following examinees may a VE not administer an examination?

Select	Answer
A	Friends of the VE
B	All these choices are correct
C	Relatives of the VE as listed in the FCC rules
D	Employees of the VE

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

8. - E2A11

What type of antenna can be used to minimize the effects of spin modulation and Faraday rotation?

Select	Answer
A	A circularly polarized antenna
B	An isotropic antenna
C	A linearly polarized antenna
D	A log-periodic dipole array

9. - E2B04

How is color information sent in analog SSTV?

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

10. - E2C02

Which of the following best describes the term self-spotting? in connection with HF contest operating?

Select	Answer
A	The often-prohibited practice of posting one's own call sign and frequency on a spotting network
B	The acceptable practice of manually posting the call signs of stations on a spotting network
C	A manual technique for rapidly zero beating or tuning to a station's frequency before calling that station
D	An automatic method for rapidly zero beating or tuning to a station's frequency before calling that station

11. - E2D08

What type of packet frame is used to transmit APRS beacon data?

Select	Answer
A	Unnumbered Information
B	Acknowledgement
C	Disconnect
D	Connect

12. - E2E11

What is the difference between direct FSK and audio FSK?

Select	Answer
A	Only direct FSK can be decoded by computer
B	Direct FSK applies the data signal to the transmitter VFO, while AFSK transmits tones via phone
C	Direct FSK can transmit faster baud rates
D	Direct FSK occupies less bandwidth

13. - E3A05

Tropospheric propagation of microwave signals often occurs in association with what phenomenon?

Select	Answer
A	Grayline
B	Sprites and jets
C	Lightning discharges
D	Warm and cold fronts

14. - E3B10

Why is chordal hop propagation desirable?

Select	Answer
A	The MUF for chordal hop propagation is much lower than for normal skip propagation
B	Signals travel faster along ionospheric chords
C	Atmospheric noise is lower in the direction of chordal hop propagation
D	The signal experiences less loss compared to multi-hop using Earth as a reflector

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	Polar
B	Sporadic E
C	Transequatorial
D	NVIS

16. - E4A11

How should an antenna analyzer be connected when measuring antenna resonance and feed point impedance?

Select	Answer
A	Loosely couple the analyzer near the antenna base
B	Connect the antenna feed line directly to the analyzer's connector
C	Loosely couple the antenna and a dummy load to the analyzer
D	Connect the analyzer via a high-impedance transformer to the antenna

17. - E4B11

Which of the following can be measured with a vector network analyzer?

Select	Answer
A	All these choices are correct
B	Input impedance
C	Output impedance
D	Reflection coefficient

18. - E4C12

Which of the following has the largest effect on an SDR receiver's dynamic range?

Select	Answer
A	RAM speed used for data storage
B	Anti-aliasing input filter bandwidth
C	Analog-to-digital converter sample width in bits
D	CPU register width in bits

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	Adjacent channel interference
B	Neutralization
C	Amplifier desensitization
D	Intermodulation

20. - E4E05

How can radio frequency interference from an AC motor be suppressed?

Select	Answer
A	By installing a bypass capacitor in series with the motor leads
B	By using a ground-fault current interrupter in the circuit used to power the motor
C	By installing a high-pass filter in series with the motor's power leads
D	By installing a brute-force AC-line filter in series with the motor leads

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 inductive reactance
C	High, as compared to the circuit resistance
D	Approximately equal to capacitive reactance

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

23. - E5C04

What coordinate system is often used to display the resistive, inductive, and/or capacitive reactance components of impedance?

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

24. - E5D15

What is the power factor of an RL circuit having a 45-degree phase angle between the voltage and the current?

Select	Answer
A	0.707
B	0.866
C	1.0
D	0.5

25. - E6A12

Why do many MOSFET devices have internally connected Zener diodes on the gates?

Select	Answer
A	To provide a voltage reference for the correct amount of reverse-bias gate voltage
B	To protect the substrate from excessive voltages
C	To keep the gate voltage within specifications and prevent the device from overheating
D	To reduce the chance of static damage to the gate

26. - E6B02

What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

Select	Answer
A	More constant reverse avalanche voltage
B	Much higher reverse voltage breakdown
C	Longer carrier retention time
D	Less forward voltage drop

27. - E6C06

Why do CMOS digital integrated circuits have high immunity to noise on the input signal or power supply?

Select	Answer
A	The input switching threshold is about one-half the power supply voltage
B	Large bypass capacitance is inherent
C	The input switching threshold is about two times the power supply voltage
D	Bandwidth is very limited

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

29. - E6E02

Which of the following device packages is a through-hole type?

Select	Answer
A	SOT
B	DIP
C	PLCC
D	Ball grid array

30. - E6F04

What is the photovoltaic effect?

Select	Answer
A	The conversion of light to electrical energy
B	The tendency of a battery to discharge when exposed to light
C	The conversion of voltage to current when exposed to light
D	The conversion of electrical energy to mechanical energy

31. - E7A09

What logical operation is performed by an exclusive NOR gate?

Select	Answer
A	It produces logic 1 at its output only if all inputs are logic 1
B	It produces logic 1 at its output if only one input is logic 1
C	It produces logic 0 at its output only if all inputs are logic 0
D	It produces logic 0 at its output if only one input is logic 1

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

33. - E7C06

What are the distinguishing features of an elliptical filter?

Select	Answer
A	Gradual passband rolloff with extreme stop band ripple
B	Extremely flat response over its pass band with gradually rounded stop band corners
C	Extremely sharp cutoff with one or more notches in the stop band
D	Gradual passband rolloff with minimal stop band ripple

34. - E7D13

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

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

35. - E7E10

How does a diode envelope detector function?

Select	Answer
A	By breakdown of the Zener voltage
B	By sensing the change of reactance in the diode with respect to frequency
C	By mixing signals with noise in the transition region of the diode
D	By rectification and filtering of RF signals

36. - E7F09

Why is an anti-aliasing digital filter required in a digital decimator?

Select	Answer
A	It removes low-frequency signal components to eliminate the need for DC restoration
B	It notches out the sampling frequency to avoid sampling errors
C	It peaks the response of the decimator, improving bandwidth
D	It removes high-frequency signal components that would otherwise be reproduced as lower frequency components

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

38. - E7H14

What is a phase-locked loop circuit?

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

39. - E8A08

Why would a direct or flash conversion analog-to-digital converter be useful for a software defined radio?

Select	Answer
A	Very low power consumption decreases frequency drift
B	Immunity to out-of-sequence coding reduces spurious responses
C	All these choices are correct
D	Very high speed allows digitizing high frequencies

40. - E8B11

What is digital time division multiplexing?

Select	Answer
A	Two or more signals are quadrature modulated to increase bandwidth efficiency
B	Two or more signals are arranged to share discrete time slots of a data transmission
C	Two or more data streams are assigned to discrete sub-carriers on an FM transmitter
D	Two or more data streams share the same channel by transmitting time of transmission as the sub-carrier

41. - E8C12

What factors affect the bandwidth of a transmitted CW signal?

Select	Answer
A	IF bandwidth and Q
B	All these choices are correct
C	Keying speed and shape factor (rise and fall time)
D	Modulation index and output power

42. - E8D03

How does the spread spectrum technique of frequency hopping work?

Select	Answer
A	A binary bit stream is used to shift the phase of an RF carrier very rapidly in a pseudorandom sequence
B	If interference is detected by the receiver it will signal the transmitter to change frequencies
C	The frequency of the transmitted signal is changed very rapidly according to a pseudorandom sequence also used by the receiving station
D	If interference is detected by the receiver it will signal the transmitter to wait until the frequency is clear

43. - E9A05

What is included in the total resistance of an antenna system?

Select	Answer
A	Transmission-line resistance plus radiation resistance
B	Radiation resistance plus space impedance
C	Radiation resistance plus transmission resistance
D	Radiation resistance plus loss resistance

44. - E9B05

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

Select	Answer
A	Radiation resistance
B	Polarization
C	Azimuth
D	Elevation

45. - E9C11

How is the far-field elevation pattern of a vertically polarized antenna affected by being mounted over seawater versus soil?

Select	Answer
A	The low-angle radiation decreases
B	The low-angle radiation increases
C	Additional higher vertical angle lobes will appear
D	Fewer vertical angle lobes will be present

46. - E9D11

Which of the following conductors would be best for minimizing losses in a station's RF ground system?

Select	Answer
A	Resistive wire, such as spark plug wire
B	Solid wire
C	Wide flat copper strap
D	Stranded wire

47. - E9E09

Which of the following is used to shunt-feed a grounded tower at its base?

Select	Answer
A	All these choices are correct
B	Double-bazooka match
C	Hairpin match
D	Gamma match

48. - E9F02

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

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

49. - E9G08

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

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

50. - E9H06

What is the triangulation method of direction finding?

Select	Answer
A	Antenna headings from several different receiving locations are used to locate the signal source
B	The geometric angles of sky waves from the source are used to determine its position
C	A fixed receiving station plots three headings to the signal source
D	A fixed receiving station uses three different antennas to plot the location of the signal source

Figure E9-2