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

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1. - E0A05

What is one of the potential hazards of operating in the amateur radio microwave bands?

Select	Answer
A	Microwaves are ionizing radiation
B	Microwaves often travel long distances by ionospheric reflection
C	The high gain antennas commonly used can result in high exposure levels
D	The extremely high frequency energy can damage the joints of antenna structures

2. - E1A07

What is the maximum power permitted on the 2200 meter band?

Select	Answer
A	5 watts EIRP (Equivalent isotropic radiated power)
B	1 watt EIRP (Equivalent isotropic radiated power)
C	100 watts PEP
D	50 watts PEP

3. - E1B01

Which of the following constitutes a spurious emission?

Select	Answer
A	An emission outside the signal's necessary bandwidth that can be reduced or eliminated without affecting the information transmitted
B	A signal transmitted to prevent its detection by any station other than the intended recipient
C	An amateur station transmission made without the proper call sign identification
D	Any transmitted signal that unintentionally interferes with another licensed radio station

4. - E1C10

What is the permitted mean power of any spurious emission relative to the mean power of the fundamental emission from a station transmitter or external RF amplifier installed after January 1, 2003 and transmitting on a frequency below 30 MHz?

Select	Answer
A	At least 53 dB below
B	At least 43 dB below
C	At least 63 dB below
D	At least 73 dB below

5. - E1D10

Which amateur stations are eligible to be telecommand stations of space stations (subject to the privileges of the class of operator license held by the control operator of the station)?

Select	Answer
A	All these choices are correct
B	Any amateur station designated by NASA
C	Any amateur station so designated by the space station licensee
D	Any amateur station so designated by the ITU

6. - E1E07

What should a VE do if a candidate fails to comply with the examiner's instructions during an amateur operator license examination?

Select	Answer
A	Warn the candidate that continued failure to comply will result in termination of the examination
B	Immediately terminate the candidate's examination
C	Immediately terminate everyone's examination and close the session
D	Allow the candidate to complete the examination, but invalidate the results

7. - E1F07

When may an amateur station send a message to a business?

Select	Answer
A	When transmitting international third-party communications
B	When neither the amateur nor his or her employer has a pecuniary interest in the communications
C	When the control operator is employed by the FCC or another government agency
D	When the total money involved does not exceed $25

8. - E2A13

Which of the following techniques is normally used by low Earth orbiting digital satellites to relay messages around the world?

Select	Answer
A	Store-and-forward
B	Multi-satellite relaying
C	Digipeating
D	Node hopping

9. - E2B05

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

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

10. - E2C09

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

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

11. - E2D11

Which of the following data are used by the APRS network to communicate station location?

Select	Answer
A	Radio direction finding spectrum analysis
B	Latitude and longitude
C	Time and frequency
D	Polar coordinates

12. - E2E06

What is the most common data rate used for HF packet?

Select	Answer
A	110 baud
B	48 baud
C	1200 baud
D	300 baud

13. - E3A14

What is meant by circularly polarized electromagnetic waves?

Select	Answer
A	Waves that circle the Earth
B	Waves with an electric field bent into a circular shape
C	Waves with a rotating electric field
D	Waves produced by a loop antenna

14. - E3B06

Which of the following amateur bands most frequently provides long-path propagation?

Select	Answer
A	80 meters
B	20 meters
C	10 meters
D	6 meters

15. - E3C02

What is indicated by a rising A or K index?

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

16. - E4A03

Which of the following test instruments is used to display spurious signals and/or intermodulation distortion products generated by an SSB transmitter?

Select	Answer
A	A time-domain reflectometer
B	A wattmeter
C	A spectrum analyzer
D	A logic analyzer

17. - E4B10

Which of the following methods measures intermodulation distortion in an SSB transmitter?

Select	Answer
A	Modulate the transmitter using two RF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
B	Modulate the transmitter using two AF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
C	Modulate the transmitter using two AF signals having harmonically related frequencies and observe the RF output with a peak reading wattmeter
D	Modulate the transmitter using two RF signals having harmonically related frequencies and observe the RF output with a logic analyzer

18. - E4C15

What is reciprocal mixing?

Select	Answer
A	Two digital signals combining from alternate time slots
B	In-phase signals cancelling in a mixer resulting in loss of receiver sensitivity
C	Local oscillator phase noise mixing with adjacent strong signals to create interference to desired signals
D	Two out-of-band signals mixing to generate an in-band spurious signal

19. - E4D11

Why are odd-order intermodulation products, created within a receiver, of particular interest compared to other products?

Select	Answer
A	Odd-order products of two signals in the band of interest are also likely to be within the band
B	Odd-order intermodulation produces three products for every input signal within the band of interest
C	Odd-order products are an indication of poor image rejection
D	Odd-order products overload the IF filters

20. - E4E11

What could cause local AM broadcast band signals to combine to generate spurious signals in the MF or HF bands?

Select	Answer
A	You are receiving skywave signals from a distant station
B	Your station receiver IF amplifier stage is defective
C	One or more of the broadcast stations is transmitting an over-modulated signal
D	Nearby corroded metal joints are mixing and re-radiating the broadcast signals

21. - E5A11

What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150?

Select	Answer
A	47.3 kHz
B	315.6 Hz
C	23.67 kHz
D	157.8 Hz

22. - E5B01

What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the applied voltage or to discharge to 36.8% of its initial voltage?

Select	Answer
A	An exponential rate of one
B	One exponential period
C	One time constant
D	A time factor of one

23. - E5C12

Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and a 19-picofarad capacitor at 21.200 MHz?

Select	Answer
A	Point 8
B	Point 3
C	Point 7
D	Point 1

24. - E5D03

What is microstrip?

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

25. - E6A03

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

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

26. - E6B08

Which of the following is a Schottky barrier diode?

Select	Answer
A	Metal-semiconductor junction
B	PIN junction
C	Thermionic emission diode
D	Electrolytic rectifier

27. - E6C05

What is an advantage of CMOS logic devices over TTL devices?

Select	Answer
A	Immune to damage from static discharge
B	Lower distortion
C	Differential output capability
D	Lower power consumption

28. - E6D11

Which type of core material decreases inductance when inserted into a coil?

Select	Answer
A	Ceramic
B	Powdered iron
C	Ferrite
D	Brass

29. - E6E08

How is power supplied to the most common type of MMIC?

Select	Answer
A	Through a resistor and/or RF choke connected to the amplifier output lead
B	MMICs require no operating bias
C	Directly to the bias voltage (VCC IN) lead
D	Through a capacitor and RF choke connected to the amplifier input lead

30. - E6F09

What is the efficiency of a photovoltaic cell?

Select	Answer
A	The output RF power divided by the input DC power
B	The open-circuit voltage divided by the short-circuit current under full illumination
C	The relative fraction of light that is converted to current
D	Cost per kilowatt-hour generated

31. - E7A10

What is a truth table?

Select	Answer
A	A list of inputs and corresponding outputs for a digital device
B	A table of logic symbols that indicate the logic states of an op-amp
C	A table of logic symbols that indicate the high logic states of an op-amp
D	A diagram showing logic states when the digital device output is true

32. - E7B18

What is a characteristic of a grounded-grid amplifier?

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

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

34. - E7D01

How does a linear electronic voltage regulator work?

Select	Answer
A	The conduction of a control element is varied to maintain a constant output voltage
B	It eliminates the need for a pass transistor
C	The control element duty cycle is proportional to the line or load conditions
D	It has a ramp voltage as its output

35. - E7E04

What is one way a single-sideband phone signal can be generated?

Select	Answer
A	By driving a product detector with a DSB signal
B	By using a loop modulator followed by a mixer
C	By using a balanced modulator followed by a filter
D	By using a reactance modulator followed by a mixer

36. - E7F03

What type of digital signal processing filter is used to generate an SSB signal?

Select	Answer
A	A Hilbert-transform filter
B	An elliptical filter
C	A notch filter
D	An adaptive filter

37. - E7G12

What is an operational amplifier?

Select	Answer
A	An amplifier used to increase the average output of frequency modulated amateur signals to the legal limit
B	A high-gain, direct-coupled differential amplifier with very high input impedance and very low output impedance
C	A RF amplifier used in the UHF and microwave regions
D	A digital audio amplifier whose characteristics are determined by components external to the amplifier

38. - E7H02

What is a microphonic?

Select	Answer
A	Changes in oscillator frequency due to mechanical vibration
B	Distortion caused by RF pickup on the microphone cable
C	An IC used for amplifying microphone signals
D	Excess loading of the microphone by an oscillator

39. - E8A02

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

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

40. - E8B02

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

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

41. - E8C12

What factors affect the bandwidth of a transmitted CW signal?

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

42. - E8D06

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

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

43. - E9A05

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

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

44. - E9B11

What is a disadvantage of decreasing the number of wire segments in an antenna model below 10 segments per half-wavelength?

Select	Answer
A	Ground conductivity will not be accurately modeled
B	The computed feed point impedance may be incorrect
C	The resulting design will favor radiation of harmonic energy
D	The antenna will become mechanically unstable

45. - E9C05

Which of the following is a type of OCFD antenna?

Select	Answer
A	A folded dipole center-fed with 300-ohm transmission line
B	A multiband dipole antenna using one-way circular polarization for frequency diversity
C	A dipole fed approximately 1/3 the way from one end with a 4:1 balun to provide multiband operation
D	A remotely tunable dipole antenna using orthogonally controlled frequency diversity

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	As low as possible on the vertical radiator
C	As close to the transmitter as possible
D	At a voltage node

47. - E9E11

What is the primary purpose of phasing lines when used with an antenna having multiple driven elements?

Select	Answer
A	It ensures that each driven element operates in concert with the others to create the desired antenna pattern
B	It prevents reflected power from traveling back down the feed line and causing harmonic radiation from the transmitter
C	It allows single-band antennas to operate on other bands
D	It creates a low-angle radiation pattern

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	7.0 meters
B	10.6 meters
C	13.3 meters
D	8.5 meters

49. - E9G05

Which of the following is a common use for a Smith chart?

Select	Answer
A	Determine the length and position of an impedance matching stub
B	Determine the loss/100 feet of a transmission line, given the velocity factor and conductor materials
C	Determine the gain of an antenna given the physical and electrical parameters
D	Determine the impedance of a transmission line, given the physical dimensions

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 E5-1