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

2. - E1B10

What frequencies are authorized to an amateur station operating under RACES rules?

Select	Answer
A	Specific segments in the amateur service MF, HF, VHF and UHF bands
B	Military Auxiliary Radio System (MARS) channels
C	Specific local government channels
D	All amateur service frequencies authorized to the control operator

3. - E1C06

Which of the following statements concerning remotely controlled amateur stations is true?

Select	Answer
A	A control operator must be present at the control point
B	Repeater and auxiliary stations may not be remotely controlled
C	A control operator need not be present at the control point
D	Only Extra Class operators may be the control operator of a remote station

4. - E1D03

What is a telecommand station in the amateur satellite service?

Select	Answer
A	An amateur station that transmits telemetry consisting of measurements of upper atmosphere
B	An amateur station located more than 50 km above the Earth's surface
C	An amateur station located on the Earth's surface for communication with other Earth stations by means of Earth satellites
D	An amateur station that transmits communications to initiate, modify or terminate functions of a space station

5. - E1E03

What is a Volunteer Examiner Coordinator?

Select	Answer
A	An organization that has entered into an agreement with the FCC to coordinate amateur operator license examinations
B	The person who has entered into an agreement with the FCC to be the VE session manager
C	A person who has volunteered to administer amateur operator license examinations
D	A person who has volunteered to prepare amateur operator license examinations

6. - E1F09

Which of the following conditions apply when transmitting spread spectrum emission?

Select	Answer
A	A station transmitting SS emission must not cause harmful interference to other stations employing other authorized emissions
B	The transmitting station must be in an area regulated by the FCC or in a country that permits SS emissions
C	The transmission must not be used to obscure the meaning of any communication
D	All of these choices are correct

7. - E2A05

What do the letters in a satellite's mode designator specify?

Select	Answer
A	The uplink and downlink frequency ranges
B	Power limits for uplink and downlink transmissions
C	The polarization of uplink and downlink signals
D	The location of the ground control station

8. - E2B17

What is the approximate bandwidth of a slow-scan TV signal?

Select	Answer
A	6 MHz
B	3 kHz
C	2 MHz
D	600 Hz

9. - E2C04

What type of transmission is most often used for a ham radio mesh network?

Select	Answer
A	Frequency division multiplex in the 24 GHz band
B	Spread spectrum in the 2.4 GHz band
C	Store and forward on the 440 MHz band
D	Multiple Frequency Shift Keying in the 10 GHz band

10. - E2D14

What is one advantage of using JT65 coding?

Select	Answer
A	Easily copied by ear if necessary
B	Permits fast-scan TV transmissions over narrow bandwidth
C	The ability to decode signals which have a very low signal to noise ratio
D	Uses only a 65 Hz bandwidth

11. - E2E13

Which of the following is a possible reason that attempts to initiate contact with a digital station on a clear frequency are unsuccessful?

Select	Answer
A	All of these choices are correct
B	Another station you are unable to hear is using the frequency
C	The protocol version you are using is not the supported by the digital station
D	Your transmit frequency is incorrect

12. - E3A15

What is an electromagnetic wave?

Select	Answer
A	A wave consisting of an electric field and a magnetic field oscillating at right angles to each other
B	A wave consisting of two electric fields at parallel right angles to each other
C	A wave of alternating current, in the core of an electromagnet
D	A wave consisting of two magnetic fields at right angles to each other

13. - E3B10

What is the cause of gray-line propagation?

Select	Answer
A	In darkness, solar absorption drops greatly while atmospheric ionization remains steady
B	At midday, the Sun super heats the ionosphere causing increased refraction of radio waves
C	At twilight and sunrise, D-layer absorption is low while E-layer and F-layer propagation remains high
D	At mid-afternoon, the Sun heats the ionosphere decreasing radio wave refraction and the MUF

14. - E3C10

What does the 304A solar parameter measure?

Select	Answer
A	UV emissions at 304 angstroms, correlated to solar flux index
B	The ratio of X-Ray flux to radio flux, correlated to sunspot number
C	The solar wind velocity at 304 degrees from the solar equator, correlated to solar activity
D	The solar emission at 304 GHz, correlated to X-Ray flare levels

15. - E4A03

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

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

16. - E4B11

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	Connect the antenna feed line directly to the analyzer's connector
C	Connect the analyzer via a high-impedance transformer to the antenna
D	Loosely couple the analyzer near the antenna base

17. - E4C02

Which of the following portions of a receiver can be effective in eliminating image signal interference?

Select	Answer
A	A front-end filter or pre-selector
B	A properly adjusted product detector
C	A narrow IF filter
D	A notch filter

18. - E4D05

What transmitter frequencies would cause an intermodulation-product signal in a receiver tuned to 146.70 MHz when a nearby station transmits on 146.52 MHz?

Select	Answer
A	146.88 MHz and 146.34 MHz
B	173.35 MHz and 139.40 MHz
C	146.10 MHz and 147.30 MHz
D	146.34 MHz and 146.61 MHz

19. - E4E12

What is one disadvantage of using some types of automatic DSP notch-filters when attempting to copy CW signals?

Select	Answer
A	A DSP filter can remove the desired signal at the same time as it removes interfering signals
B	Received CW signals will appear to be modulated at the DSP clock frequency
C	Any nearby signal passing through the DSP system will overwhelm the desired signal
D	Ringing in the DSP filter will completely remove the spaces between the CW characters

20. - E5A13

What is an effect of increasing Q in a resonant circuit?

Select	Answer
A	Internal voltages and circulating currents increase
B	Phase shift can become uncontrolled
C	Parasitic effects are minimized
D	Fewer components are needed for the same performance

21. - 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	68.2 degrees with the voltage leading the current
B	14.0 degrees with the voltage lagging the current
C	14.0 degrees with the voltage leading the current
D	68.2 degrees with the voltage lagging the current

22. - E5C10

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

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

23. - E5D16

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

Select	Answer
A	0.866
B	1.73
C	0.577
D	0.5

24. - E6A13

What do the initials CMOS stand for?

Select	Answer
A	Complementary Mica-Oxide Silicon
B	Complementary Metal-Oxide Semiconductor
C	Common Mode Oscillating System
D	Common Mode Organic Silicon

25. - E6B10

In Figure E6-3, what is the schematic symbol for a light-emitting diode?

Select	Answer
A	7
B	5
C	6
D	1

26. - E6C04

What is the primary advantage of tri-state logic?

Select	Answer
A	More efficient arithmetic operations
B	Ability to connect many device outputs to a common bus
C	High speed operation
D	Low power consumption

27. - E6D05

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

Select	Answer
A	Ferrite toroids generally have lower initial permeability
B	Ferrite toroids generally have better temperature stability
C	Ferrite toroids are easier to use with surface mount technology
D	Ferrite toroids generally require fewer turns to produce a given inductance value

28. - E6E10

What is the packaging technique in which leadless components are soldered directly to circuit boards?

Select	Answer
A	Surface mount
B	Stripped lead
C	Direct soldering
D	Virtual lead mounting

29. - E6F03

What is the most common configuration of an optoisolator or optocoupler?

Select	Answer
A	A frequency modulated helium-neon laser
B	An amplitude modulated helium-neon laser
C	A lens and a photomultiplier
D	An LED and a phototransistor

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

31. - 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	Signal inversion
B	Increased overall intelligibility
C	Reduced intermodulation products
D	Signal distortion and excessive bandwidth

32. - E7C04

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

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

33. - E7D04

Which of the following types of linear voltage regulator usually make the most efficient use of the primary power source?

Select	Answer
A	A shunt regulator
B	A shunt current source
C	A series current source
D	A series regulator

34. - E7E05

What circuit is added to an FM transmitter to boost the higher audio frequencies?

Select	Answer
A	An audio prescaler
B	A de-emphasis network
C	A heterodyne suppressor
D	A pre-emphasis network

35. - E7F04

What is a common method of generating an SSB signal using digital signal processing?

Select	Answer
A	A frequency synthesizer removes the unwanted sidebands
B	Combine signals with a quadrature phase relationship
C	Mixing products are converted to voltages and subtracted by adder circuits
D	Emulation of quartz crystal filter characteristics

36. - E7G08

How does the gain of an ideal operational amplifier vary with frequency?

Select	Answer
A	It decreases linearly with increasing frequency
B	It increases linearly with increasing frequency
C	It decreases logarithmically with increasing frequency
D	It does not vary with frequency

37. - E7H02

Which describes a microphonic?

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

38. - E8A13

Which of these methods is commonly used to convert analog signals to digital signals?

Select	Answer
A	Sequential sampling
B	Level shifting
C	Harmonic regeneration
D	Phase reversal

39. - E8B04

What is the modulation index of an FM-phone signal having a maximum carrier deviation of plus or minus 6 kHz when modulated with a 2 kHz modulating frequency?

Select	Answer
A	1/3
B	6000
C	3
D	2000

40. - E8C01

How is Forward Error Correction implemented?

Select	Answer
A	By transmitting extra data that may be used to detect and correct transmission errors
B	By the receiving station repeating each block of three data characters
C	By varying the frequency shift of the transmitted signal according to a predefined algorithm
D	By transmitting a special algorithm to the receiving station along with the data characters

41. - E8D09

What is considered a good minimum IMD level for an idling PSK signal?

Select	Answer
A	-20 dB
B	+15 dB
C	-30 dB
D	+10 dB

42. - E9A06

How does the beamwidth of an antenna vary as the gain is increased?

Select	Answer
A	It decreases
B	It increases geometrically
C	It is essentially unaffected
D	It increases arithmetically

43. - E9B01

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

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

44. - E9C15

How does the radiation pattern of a horizontally polarized 3-element beam antenna vary with its height above ground?

Select	Answer
A	The main lobe takeoff angle increases with increasing height
B	The horizontal beam width decreases with height
C	The main lobe takeoff angle decreases with increasing height
D	The horizontal beam width increases with height

45. - E9D05

What is a disadvantage of using a multiband trapped antenna?

Select	Answer
A	It must be neutralized
B	It might radiate harmonics
C	It is too sharply directional at lower frequencies
D	It radiates the harmonics and fundamental equally well

46. - E9E13

What is a use for a Wilkinson divider?

Select	Answer
A	It is used to feed high-impedance antennas from a low-impedance source
B	It is used to feed low-impedance loads from a high-impedance source
C	It is used to divide power equally between two 50 ohm loads while maintaining 50 ohm input impedance
D	It divides the operating frequency of a transmitter signal so it can be used on a lower frequency band

47. - E9F03

Why is the physical length of a coaxial cable transmission line shorter than its electrical length?

Select	Answer
A	The characteristic impedance is higher in a parallel feed line
B	The surge impedance is higher in a parallel feed line
C	Skin effect is less pronounced in the coaxial cable
D	Electrical signals move more slowly in a coaxial cable than in air

48. - E9G01

Which of the following can be calculated using a Smith chart?

Select	Answer
A	Radiation resistance
B	Antenna radiation pattern
C	Radio propagation
D	Impedance along transmission lines

49. - E9H05

What is the main drawback of a wire-loop antenna for direction finding?

Select	Answer
A	It receives equally well in all directions
B	It is non-rotatable
C	It is practical for use only on VHF bands
D	It has a bidirectional pattern

50. - E0A09

Which insulating material commonly used as a thermal conductor for some types of electronic devices is extremely toxic if broken or crushed and the particles are accidentally inhaled?

Select	Answer
A	Zinc oxide
B	Mica
C	Uranium Hexafluoride
D	Beryllium Oxide

Figure E6-3

Figure E9-1