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

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1. - E1A12

With your transceiver displaying the carrier frequency of CW signals, you hear a DX station's CQ on 3.500 MHz. Is it legal to return the call using CW on the same frequency?

Select	Answer
A	Yes, the DX station initiated the contact
B	Yes, the displayed frequency is within the 80 meter CW band segment
C	No, one of the sidebands of the CW signal will be out of the band
D	No, U.S. stations are not permitted to use CW emissions below 3.525 MHz

2. - E1B11

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 63 dB below
B	At least 73 dB below
C	At least 43 dB below
D	At least 53 dB below

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	Remotely controlling a station's antenna pattern through a directional control link
C	The use of a control link between a control point and a locally controlled station
D	A station operating with its output power controlled automatically

4. - E1D09

Which UHF amateur service bands have frequencies available for a space station?

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

5. - E1E06

Who is responsible for the proper conduct and necessary supervision during an amateur operator license examination session?

Select	Answer
A	The VE session manager
B	The FCC
C	The VEC coordinating the session
D	Each administering VE

6. - E1F07

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

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

7. - E2A04

What is meant by the term mode as applied to an amateur radio satellite?

Select	Answer
A	Whether the satellite is in a polar or equatorial orbit
B	The satellite's orientation with respect to the Earth
C	The satellite's uplink and downlink frequency bands
D	The type of signals that can be relayed through the satellite

8. - E2B12

How are analog SSTV images typically transmitted on the HF bands?

Select	Answer
A	Video is converted to equivalent Baudot representation
B	Video is converted to equivalent ASCII representation
C	Varying tone frequencies representing the video are transmitted using single sideband
D	Varying tone frequencies representing the video are transmitted using PSK

9. - E2C06

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

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

10. - E2D04

What is the purpose of digital store-and-forward functions on an Amateur Radio satellite?

Select	Answer
A	To relay messages between satellites
B	To store digital messages in the satellite for later download by other stations
C	To delay download of telemetry between satellites
D	To upload operational software for the transponder

11. - E2E09

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

Select	Answer
A	RTTY
B	MT63
C	PACTOR
D	PSK31

12. - E3A10

Which type of atmospheric structure can create a path for microwave propagation?

Select	Answer
A	Dust devil
B	The jet stream
C	Temperature inversion
D	Wind shear

13. - E3B04

What is meant by the terms extraordinary and ordinary waves?

Select	Answer
A	Refracted rays and reflected waves
B	Independent waves created in the ionosphere that are elliptically polarized
C	Long path and short path waves
D	Extraordinary waves describe rare long skip propagation compared to ordinary waves which travel shorter distances

14. - E3C12

How does the maximum distance of ground-wave propagation change when the signal frequency is increased?

Select	Answer
A	It stays the same
B	It decreases
C	It increases
D	It peaks at roughly 14 MHz

15. - E4A02

Which of the following parameters would a spectrum analyzer display on the vertical and horizontal axes?

Select	Answer
A	RF amplitude and time
B	RF amplitude and frequency
C	SWR and frequency
D	SWR and time

16. - E4B17

What three test loads are used to calibrate a standard RF vector network analyzer?

Select	Answer
A	Short circuit, open circuit, and 50 ohms
B	Short circuit, open circuit, and resonant circuit
C	50 ohms through 1/8 wavelength, 1/4 wavelength, and 1/2 wavelength of coaxial cable
D	50 ohms, 75 ohms, and 90 ohms

17. - E4C08

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

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

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

20. - 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 in phase
B	The voltage and current are 180 degrees out of phase
C	The current leads the voltage by 90 degrees
D	The voltage leads the current by 90 degrees

21. - E5B13

What letter is commonly used to represent susceptance?

Select	Answer
A	B
B	Y
C	X
D	G

22. - E5C09

When using rectangular coordinates to graph the impedance of a circuit, what does the horizontal axis represent?

Select	Answer
A	Reactive component
B	The difference between the resistive and reactive components
C	Resistive component
D	The sum of the reactive and resistive components

23. - E5D08

What type of energy is stored in an electromagnetic or electrostatic field?

Select	Answer
A	Potential energy
B	Electromechanical energy
C	Thermodynamic energy
D	Kinetic energy

24. - E6A10

In Figure E6-2, what is the schematic symbol for an N-channel dual-gate MOSFET?

Select	Answer
A	6
B	5
C	4
D	2

25. - E6B07

What is the failure mechanism when a junction diode fails due to excessive current?

Select	Answer
A	Charge carrier depletion
B	Excessive junction temperature
C	Insufficient forward voltage
D	Excessive inverse voltage

26. - E6C08

In Figure E6-5, what is the schematic symbol for a NAND gate?

Select	Answer
A	3
B	4
C	2
D	1

27. - E6D08

What is one reason for using powdered-iron cores rather than ferrite cores in an inductor?

Select	Answer
A	Powdered-iron cores generally require fewer turns to produce a given inductance
B	Powdered-iron cores generally maintain their characteristics at higher currents
C	Powdered-iron cores generally have greater initial permeability
D	Powdered-iron cores use smaller diameter wire for the same inductance

28. - E6E03

Which of the following materials is likely to provide the highest frequency of operation when used in MMICs?

Select	Answer
A	Silicon dioxide
B	Silicon nitride
C	Silicon
D	Gallium nitride

29. - E6F14

Which of the following is true of LCD displays?

Select	Answer
A	All of these choices are correct
B	They are hard to view in high ambient light conditions
C	They may be hard view through polarized lenses
D	They only display alphanumeric symbols

30. - E7A02

What is the function of a decade counter digital IC?

Select	Answer
A	It produces one output pulse for every ten input pulses
B	It adds two decimal numbers together
C	It produces ten output pulses for every input pulse
D	It decodes a decimal number for display on a seven segment LED display

31. - E7B06

Which of the following amplifier types reduces or eliminates even order harmonics?

Select	Answer
A	Push-push
B	Class C
C	Push-pull
D	Class AB

32. - E7C11

Which of the following is the common name for a filter network which is equivalent to two L-networks connected back-to-back with the two inductors in series and the capacitors in shunt at the input and output?

Select	Answer
A	Cascode
B	Pi
C	Pi-L
D	Omega

33. - E7D13

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

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

34. - E7E06

Why is de-emphasis commonly used in FM communications receivers?

Select	Answer
A	For higher efficiency
B	For compatibility with transmitters using phase modulation
C	To reduce impulse noise reception
D	To remove third-order distortion products

35. - 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 removes high-frequency signal components which would otherwise be reproduced as lower frequency components
C	It notches out the sampling frequency to avoid sampling errors
D	It peaks the response of the decimator, improving bandwidth

36. - E7G01

What is the typical output impedance of an integrated circuit op-amp?

Select	Answer
A	Very high
B	Very low
C	1000 ohms
D	100 ohms

37. - E7H03

How is positive feedback supplied in a Hartley oscillator?

Select	Answer
A	Through a neutralizing capacitor
B	Through a tapped coil
C	Through a capacitive divider
D	Through link coupling

38. - E8A05

What would be the most accurate way of measuring the RMS voltage of a complex waveform?

Select	Answer
A	By using an absorption wave meter
B	By measuring the voltage with a D'Arsonval meter
C	By measuring the heating effect in a known resistor
D	By using a grid dip meter

39. - E8B02

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

Select	Answer
A	It increases 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 decreases as the RF carrier frequency increases

40. - E8C07

What is the necessary bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?

Select	Answer
A	5.76 kHz
B	4.8 kHz
C	15.36 kHz
D	9.6 kHz

41. - E8D07

What is a common cause of overmodulation of AFSK signals?

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

42. - E9A09

How is antenna efficiency calculated?

Select	Answer
A	(effective radiated power / transmitter output) x 100 percent
B	(radiation resistance / total resistance) x 100 per cent
C	(total resistance / radiation resistance) x 100 per cent
D	(radiation resistance / transmission resistance) x 100 per cent

43. - E9B07

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

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

44. - E9C07

What is the approximate feed point impedance at the center of a two-wire folded dipole antenna?

Select	Answer
A	72 ohms
B	300 ohms
C	50 ohms
D	450 ohms

45. - E9D07

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

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

46. - E9E02

What is the name of an antenna matching system that matches an unbalanced feed line to an antenna by feeding the driven element both at the center of the element and at a fraction of a wavelength to one side of center?

Select	Answer
A	The stub match
B	The epsilon match
C	The gamma match
D	The delta match

47. - E9F11

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

Select	Answer
A	An inductive reactance
B	The same as the input impedance of the final generator stage
C	The same as the characteristic impedance of the line
D	A capacitive reactance

48. - E9G04

What are the two families of circles and arcs that make up a Smith chart?

Select	Answer
A	Voltage and impedance
B	Resistance and reactance
C	Reactance and voltage
D	Resistance and voltage

49. - 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

50. - E0A02

When evaluating RF exposure levels from your station at a neighbor's home, what must you do?

Select	Answer
A	Make sure signals from your station are less than the controlled MPE limits
B	Advise your neighbors of the results of your tests
C	You need only evaluate exposure levels on your own property
D	Make sure signals from your station are less than the uncontrolled MPE limits

Figure E6-2

Figure E6-5