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

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1. - E0A01

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

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

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

3. - E1B07

To what type of regulations does PRB-1 apply?

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

4. - E1C08

What is the maximum permissible duration of a remotely controlled station's transmissions if its control link malfunctions?

Select	Answer
A	30 seconds
B	5 minutes
C	3 minutes
D	10 minutes

5. - E1D09

Which UHF amateur bands have frequencies authorized for space stations?

Select	Answer
A	70 cm and 33 cm
B	33 cm and 13 cm
C	70 cm only
D	70 cm and 13 cm

6. - E1E10

What must the administering VEs do after the administration of a successful examination for an amateur operator license?

Select	Answer
A	They must collect and send the documents to the FCC according to instructions
B	They must collect and submit the documents to the coordinating VEC for grading
C	They must collect and send the documents to the NCVEC for grading
D	They must submit the application document to the coordinating VEC according to the coordinating VEC instructions

7. - E1F11

Which of the following best describes one of the standards that must be met by an external RF power amplifier if it is to qualify for a grant of FCC certification?

Select	Answer
A	It must satisfy the FCC's spurious emission standards when operated at the lesser of 1500 watts or its full output power
B	It must produce full legal output when driven by not more than 5 watts of mean RF input power
C	It must be capable of external RF switching between its input and output networks
D	It must exhibit a gain of 0 dB or less over its full output range

8. - E2A10

What type of satellite appears to stay in one position in the sky?

Select	Answer
A	LEO
B	Geostationary
C	HEO
D	Geomagnetic

9. - E2B05

Which of the following describes the use of vestigial sideband in analog fast-scan TV transmissions?

Select	Answer
A	Vestigial sideband reduces bandwidth while allowing for simple video detector circuitry
B	Vestigial sideband provides high frequency emphasis to sharpen the picture
C	The vestigial sideband contains chroma information
D	The vestigial sideband carries the audio information

10. - E2C06

During a VHF/UHF contest, in which band segment would you expect to find the highest level of SSB or CW activity?

Select	Answer
A	In the middle of each band, usually on the national calling frequency
B	At the top of each band, usually in a segment reserved for contests
C	In the middle of the band, usually 25 kHz above the national calling frequency
D	In the weak signal segment of the band, with most of the activity near the calling frequency

11. - E2D04

What technology is used to track, in real time, balloons carrying amateur radio transmitters?

Select	Answer
A	Bandwidth compressed LORAN
B	Doppler shift of beacon signals
C	APRS
D	Ultrasonics

12. - E2E09

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

Select	Answer
A	PSK31
B	PACTOR
C	MT63
D	RTTY

13. - E3A11

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

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

14. - E3B03

What is the best time of day for transequatorial propagation?

Select	Answer
A	Noon
B	Afternoon or early evening
C	Morning
D	Late at night

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	NVIS
B	Sporadic E
C	Transequatorial
D	Polar

16. - E4A05

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

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

17. - E4B08

Which of the following can be used to measure the Q of a series-tuned circuit?

Select	Answer
A	The inductance to capacitance ratio
B	The resonant frequency of the circuit
C	The frequency shift
D	The bandwidth of the circuit's frequency response

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. - E4D12

What is the term for the reduction in receiver sensitivity caused by a strong signal near the received frequency?

Select	Answer
A	Squelch gain rollback
B	Cross-modulation interference
C	Quieting
D	Desensitization

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

21. - E5A08

What is the phase relationship between the current through and the voltage across a series resonant circuit at resonance?

Select	Answer
A	The voltage and current are 180 degrees out of phase
B	The voltage and current are in phase
C	The voltage leads the current by 90 degrees
D	The current leads the voltage by 90 degrees

22. - E5B07

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 500 ohms, R is 1 kilohm, and XL is 250 ohms?

Select	Answer
A	14.0 degrees with the voltage leading the current
B	14.0 degrees with the voltage lagging the current
C	68.2 degrees with the voltage leading the current
D	68.2 degrees with the voltage lagging 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	Maidenhead grid
B	Elliptical coordinates
C	Rectangular coordinates
D	Faraday grid

24. - E5D02

Why is it important to keep lead lengths short for components used in circuits for VHF and above?

Select	Answer
A	To maintain component lifetime
B	To avoid unwanted inductive reactance
C	All these choices are correct
D	To increase the thermal time constant

25. - E6A03

Why does a PN-junction diode not conduct current when reverse biased?

Select	Answer
A	Holes in P-type material and electrons in the N-type material are separated by the applied voltage, widening the depletion region
B	Only N-type semiconductor material can conduct current
C	Only P-type semiconductor material can conduct current
D	Excess holes in P-type material combine with the electrons in N-type material, converting the entire diode into an insulator

26. - E6B01

What is the most useful characteristic of a Zener diode?

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

27. - E6C04

Which of the following is an advantage of BiCMOS logic?

Select	Answer
A	Its simplicity results in much less expensive devices than standard CMOS
B	All these choices are correct
C	It has the high input impedance of CMOS and the low output impedance of bipolar transistors
D	It is immune to electrostatic damage

28. - E6D02

What is the equivalent circuit of a quartz crystal?

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

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	Plate current that is controlled by a control grid
C	The ability to retrieve information from a single signal even in the presence of other strong signals
D	Nearly infinite gain, very high input impedance, and very low output impedance

30. - E6F05

Which describes an optical shaft encoder?

Select	Answer
A	A device that detects rotation of a control by interrupting a light source with a patterned wheel
B	A device for generating RTTY signals by means of a rotating light source
C	A device that measures the strength of a beam of light using analog to digital conversion
D	A digital encryption device often used to encrypt spacecraft control signals

31. - E7A02

What is the function of a decade counter?

Select	Answer
A	It decodes a binary number for display on a seven-segment LED display
B	It decodes a decimal number for display on a seven-segment LED display
C	It produces 10 output pulses for every input pulse
D	It produces one output pulse for every 10 input pulses

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	Reduced intermodulation products
C	Signal inversion
D	Signal distortion and excessive bandwidth

33. - E7C06

What are the distinguishing features of an elliptical filter?

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

34. - E7D08

What type of circuit is shown in Figure E7-2?

Select	Answer
A	Linear voltage regulator
B	Switching voltage regulator
C	Monostable multivibrator
D	Grounded emitter amplifier

35. - E7E08

What are the principal frequencies that appear at the output of a mixer circuit?

Select	Answer
A	Two and four times the original frequency
B	1.414 and 0.707 times the input frequency
C	The two input frequencies along with their sum and difference frequencies
D	The square root of the product of input frequencies

36. - E7F05

How frequently must an analog signal be sampled by an analog-to-digital converter so that the signal can be accurately reproduced?

Select	Answer
A	At four times the rate of the highest frequency component of the signal
B	At least twice the rate of the highest frequency component of the signal
C	At least half the rate of the highest frequency component of the signal
D	At the same rate as the highest frequency component of the signal

37. - E7G07

What magnitude of voltage gain can be expected from the circuit in Figure E73 when R1 is 10 ohms and RF is 470 ohms?

Select	Answer
A	47
B	24
C	0.21
D	94

38. - E7H10

What information is contained in the lookup table of a direct digital synthesizer (DDS)?

Select	Answer
A	The phase relationship between a voltage-controlled oscillator and the output waveform
B	Frequently used receiver and transmitter frequencies
C	Amplitude values that represent the desired waveform
D	The phase relationship between a reference oscillator and the output waveform

39. - E8A06

What is the approximate ratio of PEP-to-average power in a typical single-sideband phone signal?

Select	Answer
A	1 to 1
B	100 to 1
C	25 to 1
D	2.5 to 1

40. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

Select	Answer
A	A frequency modulation technique that uses non-harmonically related frequencies
B	A digital modulation technique using subcarriers at frequencies chosen to avoid intersymbol interference
C	A digital mode for narrow-band, slow-speed transmissions
D	A bandwidth compression technique using Fourier transforms

41. - E8C08

How does ARQ accomplish error correction?

Select	Answer
A	If errors are detected, a retransmission is requested
B	Special binary codes provide automatic correction
C	If errors are detected, redundant data is substituted
D	Special polynomial codes provide automatic correction

42. - E8D11

What is one advantage of using ASCII code for data communications?

Select	Answer
A	It contains fewer information bits per character than any other code
B	It uses one character as a shift code to send numeric and special characters
C	It includes built-in error correction features
D	It is possible to transmit both upper and lower case text

43. - E9A07

What is the effective isotropic radiated power of a repeater station with 200 watts transmitter power output, 2 dB feed line loss, 2.8 dB duplexer loss, 1.2 dB circulator loss, and 7 dBi antenna gain?

Select	Answer
A	63.2 watts
B	159 watts
C	632 watts
D	252 watts

44. - E9B03

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

Select	Answer
A	12 dB
B	24 dB
C	14 dB
D	18 dB

45. - E9C03

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed in phase?

Select	Answer
A	Cardioid
B	Omni-directional
C	A Figure-8 end-fire along the axis of the array
D	A Figure-8 broadside to the axis of the array

46. - E9D04

Why should an HF mobile antenna loading coil have a high ratio of reactance to resistance?

Select	Answer
A	To swamp out harmonics
B	To minimize losses
C	To minimize the Q
D	To lower the radiation angle

47. - E9E06

Which of these feed line impedances would be suitable for constructing a quarter-wave Q-section for matching a 100-ohm loop to 50-ohm feed line?

Select	Answer
A	62 ohms
B	450 ohms
C	50 ohms
D	75 ohms

48. - E9F09

What is the approximate physical length of a foam polyethylene dielectric coaxial transmission line that is electrically 1/4 wavelength long at 7.2 MHz?

Select	Answer
A	8.3 meters
B	6.9 meters
C	10.4 meters
D	5.2 meters

49. - E9G03

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

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

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 one or more wavelengths long
C	It should be configured as a four-sided loop
D	It must be mounted more than 1 wavelength above ground

Figure E7-2

Figure E9-1