US Amateur Radio - Amateur Extra (Element 4, 2016-2020) Practice Test

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1. - E1A07

Which amateur band requires transmission on specific channels rather than on a range of frequencies?

Select	Answer
A	12 meter band
B	60 meter band
C	30 meter band
D	17 meter band

2. - E1B04

What must be done before placing an amateur station within an officially designated wilderness area or wildlife preserve, or an area listed in the National Register of Historical Places?

Select	Answer
A	A form FSD-15 must be submitted to the Department of the Interior
B	An Environmental Assessment must be submitted to the FCC
C	A letter of intent must be filed with the National Audubon Society
D	A proposal must be submitted to the National Park Service

3. - E1C02

What is meant by automatic control of a station?

Select	Answer
A	The use of devices and procedures for control so that the control operator does not have to be present at a control point
B	A station operating with its output power controlled automatically
C	The use of a control link between a control point and a locally controlled station
D	Remotely controlling a station's antenna pattern through a directional control link

4. - E1D05

What class of licensee is authorized to be the control operator of a space station?

Select	Answer
A	Only General, Advanced or Amateur Extra Class
B	Only Amateur Extra Class
C	All except Technician Class
D	Any class with appropriate operator privileges

5. - E1E14

For which types of out-of-pocket expenses do the Part 97 rules state that VEs and VECs may be reimbursed?

Select	Answer
A	No expenses are authorized for reimbursement
B	Teaching an amateur operator license examination preparation course
C	Preparing, processing, administering and coordinating an examination for an amateur radio license
D	Providing amateur operator license examination preparation training materials

6. - 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	440 MHz - 450 MHz
B	222 MHz - 223 MHz
C	420 MHz - 430 MHz
D	53 MHz - 54 MHz

7. - E2A12

What is one way to predict the location of a satellite at a given time?

Select	Answer
A	By adding the mean anomaly to the orbital inclination
B	By subtracting the mean anomaly from the orbital inclination
C	By calculations using the Keplerian elements for the specified satellite
D	By means of the Doppler data for the specified satellite

8. - 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	A type of modulation in which one sideband is inverted
C	Spread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation
D	Amplitude modulation in which one complete sideband and a portion of the other are transmitted

9. - E2C02

Which of the following best describes the term self-spotting in regards to HF contest operating?

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

10. - E2D08

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

Select	Answer
A	Disconnect
B	Unnumbered Information
C	Connect
D	Acknowledgement

11. - E2E11

What is the difference between direct FSK and audio FSK?

Select	Answer
A	Audio FSK has a superior frequency response
B	Direct FSK applies the data signal to the transmitter VFO
C	Audio FSK can be performed anywhere in the transmit chain
D	Direct FSK uses a DC-coupled data connection

12. - E3A09

Which of the following frequency range is most suited for meteor scatter communications?

Select	Answer
A	10 MHz - 14 MHz
B	1.8 MHz - 1.9 MHz
C	28 MHz - 148 MHz
D	220 MHz - 450 MHz

13. - E3B14

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

Select	Answer
A	They are bent toward the magnetic poles
B	They become elliptically polarized
C	Their polarization is randomly modified
D	They become phase-locked

14. - E3C14

Why does the radio-path horizon distance exceed the geometric horizon?

Select	Answer
A	Downward bending due to density variations in the atmosphere
B	Downward bending due to aurora refraction
C	E-region skip
D	D-region skip

15. - E4A14

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

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

16. - E4B01

Which of the following factors most affects the accuracy of a frequency counter?

Select	Answer
A	Decade divider accuracy
B	Temperature coefficient of the logic
C	Input attenuator accuracy
D	Time base accuracy

17. - E4C05

What does a value of -174 dBm/Hz represent with regard to the noise floor of a receiver?

Select	Answer
A	The theoretical noise at the input of a perfect receiver at room temperature
B	The noise figure of a 1 Hz bandwidth receiver
C	The galactic noise contribution to minimum detectable signal
D	The minimum detectable signal as a function of receive frequency

18. - E4D08

What causes intermodulation in an electronic circuit?

Select	Answer
A	Too little gain
B	Positive feedback
C	Nonlinear circuits or devices
D	Lack of neutralization

19. - E4E05

How can noise from an electric motor be suppressed?

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

20. - E5A05

What is the magnitude of the current at the input of a series RLC circuit as the frequency goes through resonance?

Select	Answer
A	R/L
B	L/R
C	Minimum
D	Maximum

21. - E5B11

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 25 ohms, R is 100 ohms, and XL is 50 ohms?

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

22. - E5C08

What coordinate system is often used to display the phase angle of a circuit containing resistance, inductive and/or capacitive reactance?

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

23. - E5D05

Which parasitic characteristic increases with conductor length?

Select	Answer
A	Inductance
B	Permittivity
C	Permeability
D	Malleability

24. - E6A09

What is a depletion-mode FET?

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

25. - E6B12

What is one common use for PIN diodes?

Select	Answer
A	As a high voltage rectifier
B	As a constant current source
C	As an RF switch
D	As a constant voltage source

26. - E6C05

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

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

27. - E6D07

What is the usable frequency range of inductors that use toroidal cores, assuming a correct selection of core material for the frequency being used?

Select	Answer
A	From about 100 kHz to at least 1000 GHz
B	From a few kHz to no more than 30 MHz
C	From approximately 10 Hz to no more than 3000 kHz
D	From less than 20 Hz to approximately 300 MHz

28. - E6E05

Which of the following noise figure values is typical of a low-noise UHF preamplifier?

Select	Answer
A	2 dB
B	44 dBm
C	-10 dB
D	-20 dBm

29. - E6F05

Which describes an optical shaft encoder?

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

30. - 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 "0" at its output if any single input is logic "1"
C	It produces logic "1" at its output if any single input is logic "1"
D	It produces logic "0" at its output only if all inputs are logic "0"

31. - E7B10

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

Select	Answer
A	Load resistors
B	Feedback
C	Fixed bias
D	Self bias

32. - E7C04

How does an impedance-matching circuit transform a complex impedance to a resistive impedance?

Select	Answer
A	Network resistances are substituted for load resistances and reactances are matched to the resistances
B	It cancels the reactive part of the impedance and changes the resistive part to a desired value
C	It introduces negative resistance to cancel the resistive part of impedance
D	It introduces transconductance to cancel the reactive part of impedance

33. - E7D07

What is the purpose of C2 in the circuit shown in Figure E7-3?

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

34. - E7E12

What is a frequency discriminator stage in a FM receiver?

Select	Answer
A	A circuit for detecting FM signals
B	An automatic band-switching circuit
C	An FM generator circuit
D	A circuit for filtering two closely adjacent signals

35. - E7F07

What function can a Fast Fourier Transform perform?

Select	Answer
A	Converting analog signals to digital form
B	Converting 8-bit data to 16 bit data
C	Converting digital signals from the time domain to the frequency domain
D	Converting digital signals to analog form

36. - E7G06

Which of the following is the most appropriate use of an op-amp active filter?

Select	Answer
A	For smoothing power supply output
B	As a high-pass filter used to block RFI at the input to receivers
C	As a low-pass filter used between a transmitter and a transmission line
D	As an audio filter in a receiver

37. - E7H06

Which of the following oscillator circuits are commonly used in VFOs?

Select	Answer
A	Armstrong and deForest
B	Pierce and Zener
C	Colpitts and Hartley
D	Negative feedback and balanced feedback

38. - E8A09

How many levels can an analog-to-digital converter with 8 bit resolution encode?

Select	Answer
A	256 divided by the gain of the input amplifier
B	8 multiplied by the gain of the input amplifier
C	256
D	8

39. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

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

40. - E8C08

How does ARQ accomplish error correction?

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

41. - E8D07

What is a common cause of overmodulation of AFSK signals?

Select	Answer
A	Excessive transmit audio levels
B	Bit errors in the modem
C	Ground loops
D	Excessive numbers of retries

42. - E9A14

What is meant by the radiation resistance of an antenna?

Select	Answer
A	The specific impedance of the antenna
B	The resistance in the atmosphere that an antenna must overcome to be able to radiate a signal
C	The value of a resistance that would dissipate the same amount of power as that radiated from an antenna
D	The combined losses of the antenna elements and feed line

43. - E9B01

In the antenna radiation pattern shown in Figure E9-1, what is the 3 dB beam-width?

Select	Answer
A	25 degrees
B	50 degrees
C	75 degrees
D	30 degrees

44. - E9C01

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed 180 degrees out of phase?

Select	Answer
A	A figure-8 broadside to the axis of the array
B	Cardioid
C	A figure-8 oriented along the axis of the array
D	Omni-directional

45. - E9D07

What is an advantage of using top loading in a shortened HF vertical antenna?

Select	Answer
A	Greater structural strength
B	Lower Q
C	Higher losses
D	Improved radiation efficiency

46. - E9E11

What is an effective way of matching a feed line to a VHF or UHF antenna when the impedances of both the antenna and feed line are unknown?

Select	Answer
A	Use the universal stub matching technique
B	Connect a series-resonant LC network across the antenna feed terminals
C	Connect a parallel-resonant LC network across the antenna feed terminals
D	Use a 50 ohm 1:1 balun between the antenna and feed line

47. - E9F02

Which of the following determines the velocity factor of a transmission line?

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

48. - E9G07

On the Smith chart shown in Figure E9-3, what is the only straight line shown?

Select	Answer
A	The current axis
B	The resistance axis
C	The voltage axis
D	The reactance axis

49. - E9H09

Which of the following describes the construction of a receiving loop antenna?

Select	Answer
A	A large circularly polarized antenna
B	A vertical antenna coupled to a feed line through an inductive loop of wire
C	A small coil of wire tightly wound around a toroidal ferrite core
D	One or more turns of wire wound in the shape of a large open coil

50. - E0A10

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

Select	Answer
A	Polymorphic silicon
B	Polychlorinated Biphenyls
C	Polyethylene
D	Polytetrafluroethylene

Figure E7-1

Figure E7-3

Figure E9-1

Figure E9-3