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. - E0A10

What toxic material may be present in some electronic components such as high voltage capacitors and transformers?

Select	Answer
A	Polytetrafluoroethylene
B	Polychlorinated biphenyls
C	Polymorphic silicon
D	Polyethylene

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	18.110 MHz
B	18.107 MHz
C	18.100 MHz
D	18.068 MHz

3. - E1B05

What is the National Radio Quiet Zone?

Select	Answer
A	An area in New Mexico surrounding the White Sands Test Area
B	An area in Puerto Rico surrounding the Arecibo Radio Telescope
C	An area surrounding the National Radio Astronomy Observatory
D	An area in Florida surrounding Cape Canaveral

4. - E1C13

What notifications must be given before transmitting on the 630 meter or 2200 meter bands?

Select	Answer
A	An environmental impact statement must be filed with the Department of the Interior
B	A special endorsement must be requested from the FCC
C	Operators must inform the FAA of their intent to operate, giving their call sign and distance to the nearest runway
D	Operators must inform the Utilities Technology Council (UTC) of their call sign and coordinates of the station

5. - E1D11

Which amateur stations are eligible to operate as Earth stations?

Select	Answer
A	Only those of Amateur Extra Class operators
B	Only those of General, Advanced or Amateur Extra Class operators
C	Any amateur station, subject to the privileges of the class of operator license held by the control operator
D	Any amateur station whose licensee has filed a pre-space notification with the FCC's International Bureau

6. - E1E04

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

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

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

8. - E2A07

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

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

9. - E2B06

What is vestigial sideband modulation?

Select	Answer
A	Narrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier
B	Spread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation
C	Amplitude modulation in which one complete sideband and a portion of the other are transmitted
D	A type of modulation in which one sideband is inverted

10. - E2C04

Which of the following frequencies are sometimes used for amateur radio mesh networks?

Select	Answer
A	Cable TV channels 41 through 43
B	The 60 meter band channel centered on 5373 kHz
C	HF frequencies where digital communications are permitted
D	Frequencies shared with various unlicensed wireless data services

11. - E2D01

Which of the following digital modes is designed for meteor scatter communications?

Select	Answer
A	MSK144
B	WSPR
C	APRS
D	Hellschreiber

12. - E2E06

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

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

13. - E3A03

When scheduling EME contacts, which of these conditions will generally result in the least path loss?

Select	Answer
A	When the moon is at apogee
B	When the MUF is above 30 MHz
C	When the moon is at perigee
D	When the moon is full

14. - E3B12

What is the primary characteristic of chordal hop propagation?

Select	Answer
A	Propagation away from the great circle bearing between stations
B	Successive ionospheric refractions without an intermediate reflection from the ground
C	Signals reflected back toward the transmitting station
D	Propagation across the geomagnetic equator

15. - E3C07

Which of the following descriptors indicates the greatest solar flare intensity?

Select	Answer
A	Class M
B	Class B
C	Class X
D	Class A

16. - E4A11

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

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

17. - E4B03

Which S parameter is equivalent to forward gain?

Select	Answer
A	S11
B	S12
C	S21
D	S22

18. - E4C08

An SDR receiver is overloaded when input signals exceed what level?

Select	Answer
A	The maximum count value of the analog-to-digital converter
B	One-half the maximum sampling buffer size
C	The reference voltage of the analog-to-digital converter
D	One-half the maximum sample rate

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	Adjacent channel interference
C	Amplifier desensitization
D	Intermodulation

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	Nearby corroded metal joints are mixing and re-radiating the broadcast signals
C	Your station receiver IF amplifier stage is defective
D	One or more of the broadcast stations is transmitting an over-modulated signal

21. - E5A14

What is the resonant frequency of an RLC circuit if R is 22 ohms, L is 50 microhenries and C is 40 picofarads?

Select	Answer
A	44.72 MHz
B	3.56 MHz
C	1.78 MHz
D	22.36 MHz

22. - E5B03

How is impedance in polar form converted to an equivalent admittance?

Select	Answer
A	Square the magnitude and subtract 90 degrees from the angle
B	Take the reciprocal of the magnitude and change the sign of the angle
C	Take the square root of the magnitude and add 180 degrees to the angle
D	Take the reciprocal of the angle and change the sign of the magnitude

23. - E5C03

Which of the following represents an inductive reactance in polar coordinates?

Select	Answer
A	A positive magnitude
B	A negative magnitude
C	A negative phase angle
D	A positive phase angle

24. - E5D05

What is the power factor of an RL circuit having a 30-degree phase angle between the voltage and the current?

Select	Answer
A	0.5
B	0.577
C	0.866
D	1.73

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. - E6B11

What is used to control the attenuation of RF signals by a PIN diode?

Select	Answer
A	Capacitance of an RF coupling capacitor
B	Reverse voltage larger than the RF signal
C	A sub-harmonic pump signal
D	Forward DC bias current

27. - E6C11

In Figure E6-3, what is the schematic symbol for the NOT operation (inverter)?

Select	Answer
A	5
B	6
C	2
D	4

28. - E6D04

Which materials are commonly used as a core in an inductor?

Select	Answer
A	Ferrite and brass
B	Teflon and Delrin
C	Cobalt and aluminum
D	Polystyrene and polyethylene

29. - E6E04

Which is the most common input and output impedance of circuits that use MMICs?

Select	Answer
A	450 ohms
B	300 ohms
C	10 ohms
D	50 ohms

30. - E6F06

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

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

31. - E7A02

What is the function of a decade counter?

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

32. - E7B05

What can be done to prevent unwanted oscillations in an RF power amplifier?

Select	Answer
A	Tune the stage for maximum SWR
B	Use a phase inverter in the output filter
C	Tune both the input and output for maximum power
D	Install parasitic suppressors and/or neutralize the stage

33. - E7C06

What are the distinguishing features of an elliptical filter?

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

34. - E7D10

What is the primary reason that a high-frequency switching type high-voltage power supply can be both less expensive and lighter in weight than a conventional power supply?

Select	Answer
A	It uses a diode bridge rectifier for increased output
B	It uses a large power factor compensation capacitor to recover power from the unused portion of the AC cycle
C	The inverter design does not require any output filtering
D	The high frequency inverter design uses much smaller transformers and filter components for an equivalent power output

35. - E7E04

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

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

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	8 bits
B	6 bits
C	10 bits
D	4 bits

37. - E7G12

What is an operational amplifier?

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

38. - E7H02

What is a microphonic?

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

39. - E8A02

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

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

40. - E8B07

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

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

41. - E8C04

What technique minimizes the bandwidth of a PSK31 signal?

Select	Answer
A	Zero-sum character encoding
B	Use of sinusoidal data pulses
C	Reed-Solomon character encoding
D	Use of trapezoidal data pulses

42. - E8D02

What spread spectrum communications technique uses a high-speed binary bit stream to shift the phase of an RF carrier?

Select	Answer
A	Phase compandored spread spectrum
B	Frequency hopping
C	Binary phase-shift keying
D	Direct sequence

43. - E9A11

Which of the following factors determines ground losses for a ground-mounted vertical antenna operating in the 3 MHz to 30 MHz range?

Select	Answer
A	The standing wave ratio
B	Soil conductivity
C	Take-off angle
D	Distance from the transmitter

44. - E9B07

How does the total amount of radiation emitted by a directional gain antenna compare with the total amount of radiation emitted from a theoretical isotropic antenna, assuming each is driven by the same amount of power?

Select	Answer
A	The total amount of radiation from the directional antenna is stronger by its front-to-back ratio
B	They are the same
C	The radiation from the isotropic antenna is 2.15 dB stronger than that from the directional antenna
D	The total amount of radiation from the directional antenna is increased by the gain of the antenna

45. - E9C12

Which of the following describes an Extended Double Zepp antenna?

Select	Answer
A	A portable antenna erected using two push support poles
B	A wideband vertical antenna constructed from precisely tapered aluminum tubing
C	An end-fed folded dipole antenna
D	A center-fed 1.25-wavelength antenna (two 5/8-wave elements in phase)

46. - E9D01

How much does the gain of an ideal parabolic dish antenna change when the operating frequency is doubled?

Select	Answer
A	3 dB
B	6 dB
C	2 dB
D	4 dB

47. - E9E09

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

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

48. - E9F10

What impedance does a 1/8-wavelength transmission line present to a generator when the line is shorted at the far end?

Select	Answer
A	Zero
B	An inductive reactance
C	The same as the characteristic impedance of the line
D	A capacitive reactance

49. - E9G08

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

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

50. - E9H06

What is the triangulation method of direction finding?

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

Figure E6-3