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

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1. - E1A02

When using a transceiver that displays the carrier frequency of phone signals, which of the following displayed frequencies represents the lowest frequency at which a properly adjusted LSB emission will be totally within the band?

Select	Answer
A	3 kHz above the lower band edge
B	1 kHz above the lower band edge
C	The exact lower band edge
D	300 Hz above the lower band edge

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

3. - E1C01

What is a remotely controlled station?

Select	Answer
A	A station controlled indirectly through a control link
B	A station operated away from its regular home location
C	A station controlled by someone other than the licensee
D	A station operating under automatic control

4. - E1D04

What is an Earth station in the amateur satellite service?

Select	Answer
A	An amateur station that transmits telemetry consisting of measurement of upper atmosphere
B	An amateur station within 50 km of the Earth's surface intended for communications with amateur stations by means of objects in space
C	Any amateur station on the surface of the Earth
D	An amateur station that is not able to communicate using amateur satellites

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

6. - E1F07

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

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

7. - E2A02

What is the direction of a descending pass for an amateur satellite?

Select	Answer
A	From north to south
B	From south to north
C	From east to west
D	From west to east

8. - E2B01

How many times per second is a new frame transmitted in a fast-scan (NTSC) television system?

Select	Answer
A	90
B	60
C	120
D	30

9. - E2C07

What is the Cabrillo format?

Select	Answer
A	The most common set of contest rules
B	A standard for submission of electronic contest logs
C	The rules of order for meetings between contest sponsors
D	A method of exchanging information during a contest QSO

10. - E2D10

How can an APRS station be used to help support a public service communications activity?

Select	Answer
A	An APRS station with a GPS unit can automatically transmit information to show a mobile station's position during the event
B	APRS stations with General Personnel Scanners can automatically relay the participant numbers and time as they pass the check points
C	All of these choices are correct
D	An APRS station with an emergency medical technician can automatically transmit medical data to the nearest hospital

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

12. - E3A04

What do Hepburn maps predict?

Select	Answer
A	Likelihood of rain-scatter along cold or warm fronts
B	Probability of tropospheric propagation
C	Locations of auroral reflecting zones
D	Sporadic E propagation

13. - E3B12

What is the primary characteristic of chordal hop propagation?

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

14. - E3C06

By how much does the VHF/UHF radio horizon distance exceed the geometric horizon?

Select	Answer
A	By approximately 50 percent of the distance
B	By approximately twice the distance
C	By approximately 15 percent of the distance
D	By approximately four times the distance

15. - E4A14

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

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

16. - E4B01

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

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

17. - E4C03

What is the term for the blocking of one FM phone signal by another, stronger FM phone signal?

Select	Answer
A	Cross-modulation interference
B	Desensitization
C	Frequency discrimination
D	Capture effect

18. - E4D06

What is the term for unwanted signals generated by the mixing of two or more signals?

Select	Answer
A	Neutralization
B	Adjacent channel interference
C	Intermodulation interference
D	Amplifier desensitization

19. - E4E06

What is a major cause of atmospheric static?

Select	Answer
A	Solar radio frequency emissions
B	Meteor showers
C	Geomagnetic storms
D	Thunderstorms

20. - E5A04

What is the magnitude of the impedance of a circuit with a resistor, an inductor and a capacitor all in parallel, at resonance?

Select	Answer
A	Approximately equal to circuit resistance
B	Low, as compared to the circuit resistance
C	Approximately equal to inductive reactance
D	Approximately equal to capacitive reactance

21. - E5B10

What is the relationship between the current through an inductor and the voltage across an inductor?

Select	Answer
A	Voltage and current are 180 degrees out of phase
B	Voltage leads current by 90 degrees
C	Voltage and current are in phase
D	Current leads voltage by 90 degrees

22. - E5C17

Which point on Figure E5-2 best represents the impedance of a series circuit consisting of a 300 ohm resistor, a 0.64-microhenry inductor and an 85-picofarad capacitor at 24.900 MHz?

Select	Answer
A	Point 5
B	Point 8
C	Point 3
D	Point 1

23. - E5D07

What determines the strength of the magnetic field around a conductor?

Select	Answer
A	The resistance divided by the current
B	The amount of current flowing through the conductor
C	The ratio of the current to the resistance
D	The diameter of the conductor

24. - E6A06

What is the beta of a bipolar junction transistor?

Select	Answer
A	The change in collector current with respect to base current
B	The switching speed of the transistor
C	The breakdown voltage of the base to collector junction
D	The frequency at which the current gain is reduced to 1

25. - E6B12

What is one common use for PIN diodes?

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

26. - E6C10

In Figure E6-5, what is the schematic symbol for a NOR gate?

Select	Answer
A	1
B	2
C	3
D	4

27. - E6D15

What is current in the primary winding of a transformer called if no load is attached to the secondary?

Select	Answer
A	Excitation current
B	Stabilizing current
C	Magnetizing current
D	Direct current

28. - E6E06

What characteristics of the MMIC make it a popular choice for VHF through microwave circuits?

Select	Answer
A	Controlled gain, low noise figure, and constant input and output impedance over the specified frequency range
B	Plate current that is controlled by a control grid
C	Nearly infinite gain, very high input impedance, and very low output impedance
D	The ability to retrieve information from a single signal even in the presence of other strong signals

29. - E6F08

Why are optoisolators often used in conjunction with solid state circuits when switching 120VAC?

Select	Answer
A	Optoisolators eliminate the effects of reflected light in the control circuit
B	Optoisolators provide impedance matching between the control circuit and power circuit
C	Optoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched
D	Optoisolators provide a low impedance link between a control circuit and a power circuit

30. - E7A04

How many flip-flops are required to divide a signal frequency by 4?

Select	Answer
A	2
B	4
C	1
D	8

31. - E7B13

In Figure E7-2, what is the purpose of R?

Select	Answer
A	Fixed bias
B	Voltage regulation
C	Emitter load
D	Collector load

32. - E7C12

Which describes a Pi-L-network used for matching a vacuum tube final amplifier to a 50 ohm unbalanced output?

Select	Answer
A	A Phase Inverter Load network
B	A network with only three discrete parts
C	A matching network in which all components are isolated from ground
D	A Pi-network with an additional series inductor on the output

33. - E7D13

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

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

34. - E7E11

Which type of detector is used for demodulating SSB signals?

Select	Answer
A	Discriminator
B	Phase comparator
C	Product detector
D	Phase detector

35. - E7F03

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

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

36. - E7G09

What will be the output voltage of the circuit shown in Figure E7-4 if R1 is 1000 ohms, RF is 10,000 ohms, and 0.23 volts DC is applied to the input?

Select	Answer
A	-2.3 volts
B	-0.23 volts
C	2.3 volts
D	0.23 volts

37. - E7H05

How is positive feedback supplied in a Pierce oscillator?

Select	Answer
A	Through link coupling
B	Through a quartz crystal
C	Through a tapped coil
D	Through a neutralizing capacitor

38. - E8A08

Why would a direct or flash conversion analog-to-digital converter be useful for a software defined radio?

Select	Answer
A	Very low power consumption decreases frequency drift
B	Very high speed allows digitizing high frequencies
C	All of these choices are correct
D	Immunity to out of sequence coding reduces spurious responses

39. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

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

40. - E8C01

How is Forward Error Correction implemented?

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

41. - E8D11

What is one advantage of using ASCII code for data communications?

Select	Answer
A	It contains fewer information bits per character than any other code
B	It includes built in error correction features
C	It is possible to transmit both upper and lower case text
D	It uses one character as a shift code to send numeric and special characters

42. - E9A14

What is meant by the radiation resistance of an antenna?

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

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 total amount of radiation from the directional antenna is stronger by its front-to-back ratio
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 radiation from the isotropic antenna is 2.15 dB stronger than that from the directional antenna

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

45. - E9D01

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

Select	Answer
A	Gain does not change
B	Gain increases by 3 dB
C	Gain increases by 6 dB
D	Gain is multiplied by 0.707

46. - E9E08

Which of the following measurements is characteristic of a mismatched transmission line?

Select	Answer
A	An SWR less than 1:1
B	A reflection coefficient greater than 1
C	An SWR greater than 1:1
D	A dielectric constant greater than 1

47. - E9F08

What is the term for the ratio of the actual speed at which a signal travels through a transmission line to the speed of light in a vacuum?

Select	Answer
A	Characteristic impedance
B	Surge impedance
C	Velocity factor
D	Standing wave ratio

48. - E9G09

What third family of circles is often added to a Smith chart during the process of solving problems?

Select	Answer
A	Coaxial-length circles
B	Radiation-pattern circles
C	Antenna-length circles
D	Standing wave ratio circles

49. - E9H07

Why is it advisable to use an RF attenuator on a receiver being used for direction finding?

Select	Answer
A	It reduces loss of received signals caused by antenna pattern nulls, thereby increasing sensitivity
B	It compensates for the effects of an isotropic antenna, thereby improving directivity
C	It prevents receiver overload which could make it difficult to determine peaks or nulls
D	It narrows the bandwidth of the received signal to improve signal to noise ratio

50. - E0A10

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

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

Figure E5-2

Figure E6-5

Figure E7-2

Figure E7-4