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

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1. - E1A08

If a station in a message forwarding system inadvertently forwards a message that is in violation of FCC rules, who is primarily accountable for the rules violation?

Select	Answer
A	The control operator of the packet bulletin board station
B	The control operators of all the stations in the system
C	The control operator of the originating station
D	The control operators of all the stations in the system not authenticating the source from which they accept communications

2. - E1B02

Which of the following factors might cause the physical location of an amateur station apparatus or antenna structure to be restricted?

Select	Answer
A	The location is in an ITU Zone designated for coordination with one or more foreign governments
B	The location is of environmental importance or significant in American history, architecture, or culture
C	The location is near an area of political conflict
D	The location is of geographical or horticultural importance

3. - E1C03

How do the control operator responsibilities of a station under automatic control differ from one under local control?

Select	Answer
A	Under automatic control the control operator is not required to be present at the control point
B	Under local control there is no control operator
C	Under automatic control there is no control operator
D	Under local control a control operator is not required to be present at a control point

4. - E1D06

Which of the following is a requirement of a space station?

Select	Answer
A	All of these choices are correct
B	The space station must be capable of terminating transmissions by telecommand when directed by the FCC
C	The space station must be capable of changing its orbit whenever such a change is ordered by NASA
D	The space station must cease all transmissions after 5 years

5. - E1E10

What must the administering VEs do after the administration of a successful examination for an amateur operator license?

Select	Answer
A	They must collect and send the documents to the FCC according to instructions
B	They must collect and send the documents to the NCVEC for grading
C	They must submit the application document to the coordinating VEC according to the coordinating VEC instructions
D	They must collect and submit the documents to the coordinating VEC for grading

6. - E1F10

What is the maximum permitted transmitter peak envelope power for an amateur station transmitting spread spectrum communications?

Select	Answer
A	1.5 kW
B	10 W
C	1.5 W
D	1 W

7. - E2A09

What do the terms L band and S band specify with regard to satellite communications?

Select	Answer
A	FM and Digital Store-and-Forward systems
B	Which sideband to use
C	The 23 centimeter and 13 centimeter bands
D	The 2 meter and 70 centimeter bands

8. - E2B19

What special operating frequency restrictions are imposed on slow scan TV transmissions?

Select	Answer
A	They are not permitted above 54 MHz
B	They are restricted to phone band segments and their bandwidth can be no greater than that of a voice signal of the same modulation type
C	None; they are allowed on all amateur frequencies
D	They are restricted to 7.245 MHz, 14.245 MHz, 21.345 MHz, and 28.945 MHz

9. - E2C02

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

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

10. - E2D07

What digital protocol is used by APRS?

Select	Answer
A	AX.25
B	PACTOR
C	AMTOR
D	802.11

11. - E2E02

What do the letters FEC mean as they relate to digital operation?

Select	Answer
A	Forward Error Correction
B	Final Error Correction
C	Fatal Error Correction
D	First Error Correction

12. - E3A13

Which emission mode is best for aurora propagation?

Select	Answer
A	SSB
B	CW
C	RTTY
D	FM

13. - E3B04

What is meant by the terms extraordinary and ordinary waves?

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

14. - E3C01

What does the term ray tracing describe in regard to radio communications?

Select	Answer
A	Determining the radiation pattern from an array of antennas
B	Modeling a radio wave's path through the ionosphere
C	The process in which an electronic display presents a pattern
D	Evaluating high voltage sources for X-Rays

15. - E4A05

What might be an advantage of a digital vs an analog oscilloscope?

Select	Answer
A	All of these choices are correct
B	Storage of traces for future reference
C	Automatic amplitude and frequency numerical readout
D	Manipulation of time base after trace capture

16. - E4B06

How much power is being absorbed by the load when a directional power meter connected between a transmitter and a terminating load reads 100 watts forward power and 25 watts reflected power?

Select	Answer
A	125 watts
B	100 watts
C	25 watts
D	75 watts

17. - E4C16

Which of the following is caused by missing codes in an SDR receiver's analog-to-digital converter?

Select	Answer
A	Distortion
B	Loss of sensitivity
C	Excess output level
D	Overload

18. - E4D14

Which of the following is a way to reduce the likelihood of receiver desensitization?

Select	Answer
A	Switch from fast AGC to slow AGC
B	Increase the receiver front end gain
C	Decrease the RF bandwidth of the receiver
D	Raise the receiver IF frequency

19. - E4E10

What is a common characteristic of interference caused by a touch controlled electrical device?

Select	Answer
A	All of these choices are correct
B	The interfering signal sounds like AC hum on an AM receiver or a carrier modulated by 60 Hz hum on a SSB or CW receiver
C	The interfering signal can be several kHz in width and usually repeats at regular intervals across a HF band
D	The interfering signal may drift slowly across the HF spectrum

20. - E5A02

What is resonance in an electrical circuit?

Select	Answer
A	The frequency at which the capacitive reactance equals the inductive reactance
B	The lowest frequency that will pass current
C	The highest frequency that will pass current
D	The frequency at which the reactive impedance equals the resistive impedance

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

22. - E5C16

Which point on Figure E5-2 best represents the impedance of a series circuit consisting of a 300 ohm resistor and a 19 picofarad capacitor at 21.200 MHz?

Select	Answer
A	Point 7
B	Point 1
C	Point 8
D	Point 3

23. - E5D18

How many watts are consumed in a circuit having a power factor of 0.71 if the apparent power is 500VA?

Select	Answer
A	355 W
B	252 W
C	1.42 mW
D	704 W

24. - E6A16

What are the majority charge carriers in N-type semiconductor material?

Select	Answer
A	Holes
B	Free neutrons
C	Free electrons
D	Free protons

25. - E6B04

What type of semiconductor device is designed for use as a voltage-controlled capacitor?

Select	Answer
A	Tunnel diode
B	Zener diode
C	Varactor diode
D	Silicon-controlled rectifier

26. - E6C14

What is the primary advantage of using a Programmable Gate Array (PGA) in a logic circuit?

Select	Answer
A	Many similar gates are less expensive than a mixture of gate types
B	All of these choices are correct
C	A PGA contains its own internal power supply
D	Complex logic functions can be created in a single integrated circuit

27. - E6D13

What is the primary cause of inductor self-resonance?

Select	Answer
A	Inductive kickback
B	Non-linear core hysteresis
C	The skin effect
D	Inter-turn capacitance

28. - E6E11

What is a characteristic of DIP packaging used for integrated circuits?

Select	Answer
A	Two chips in each package (Dual In Package)
B	Low leakage doubly insulated package
C	A total of two rows of connecting pins placed on opposite sides of the package (Dual In-line Package)
D	Package mounts in a direct inverted position

29. - E6F06

Which of these materials is affected the most by photoconductivity?

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

30. - E7A06

What is a characteristic of a monostable multivibrator?

Select	Answer
A	It stores one bit of data in either a 0 or 1 state
B	It produces a continuous square wave oscillating between 1 and 0
C	It switches momentarily to the opposite binary state and then returns to its original state after a set time
D	It maintains a constant output voltage, regardless of variations in the input voltage

31. - E7B04

Where on the load line of a Class A common emitter amplifier would bias normally be set?

Select	Answer
A	Approximately half-way between saturation and cutoff
B	At a point where the bias resistor equals the load resistor
C	At a point where the load line intersects the zero bias current curve
D	Where the load line intersects the voltage axis

32. - E7C09

What is a Jones filter as used as part of an HF receiver IF stage?

Select	Answer
A	An automatic notch filter
B	A special filter that emphasizes image responses
C	A variable bandwidth crystal lattice filter
D	A filter that removes impulse noise E7C10 (B) Which of the following filters would be the best choice for use in a 2 meter repeater duplexer? A. A crystal filter B. A cavity filter C. A DSP filter D. An L-C filter

33. - E7D13

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

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

34. - 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 loop modulator followed by a mixer
C	By driving a product detector with a DSB signal
D	By using a reactance modulator followed by a mixer

35. - 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	10 bits
B	6 bits
C	4 bits
D	8 bits

36. - E7G07

What magnitude of voltage gain can be expected from the circuit in Figure E7-4 when R1 is 10 ohms and RF is 470 ohms?

Select	Answer
A	24
B	94
C	0.21
D	47

37. - E7H08

Which of the following components can be used to reduce thermal drift in crystal oscillators?

Select	Answer
A	Toroidal inductors
B	Wirewound resistors
C	NP0 capacitors
D	Non-inductive resistors

38. - E8A13

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

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

39. - E8B06

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz when the maximum modulation frequency is 3.5 kHz?

Select	Answer
A	2.14
B	47
C	0.214
D	0.47

40. - E8C08

How does ARQ accomplish error correction?

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

41. - E8D11

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

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

42. - E9A18

What term describes station output, taking into account all gains and losses?

Select	Answer
A	Effective radiated power
B	Apparent power
C	Half-power bandwidth
D	Power factor

43. - E9B09

What type of computer program technique is commonly used for modeling antennas?

Select	Answer
A	Method of Moments
B	Graphical analysis
C	Mutual impedance analysis
D	Calculus differentiation with respect to physical properties

44. - E9C05

What is an OCFD antenna?

Select	Answer
A	An eight band dipole antenna using octophase filters
B	A remotely tunable dipole antenna using orthogonally controlled frequency diversity
C	A dipole feed approximately 1/3 the way from one end with a 4:1 balun to provide multiband operation
D	A multiband dipole antenna using one-way circular polarization for frequency diversity

45. - E9D03

Where should a high Q loading coil be placed to minimize losses in a shortened vertical antenna?

Select	Answer
A	As close to the transmitter as possible
B	Near the center of the vertical radiator
C	At a voltage node
D	As low as possible on the vertical radiator

46. - E9E09

Which of these matching systems is an effective method of connecting a 50 ohm coaxial cable feed line to a grounded tower so it can be used as a vertical antenna?

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

47. - E9F14

What impedance does a 1/2 wavelength transmission line present to a generator when the line is shorted at the far end?

Select	Answer
A	Very low impedance
B	The same as the characteristic impedance of the line
C	The same as the output impedance of the generator
D	Very high impedance

48. - E9G03

Which of the following is often determined using a Smith chart?

Select	Answer
A	Trigonometric functions
B	Satellite azimuth and elevation bearings
C	Beam headings and radiation patterns
D	Impedance and SWR values in transmission lines

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 prevents receiver overload which could make it difficult to determine peaks or nulls
C	It narrows the bandwidth of the received signal to improve signal to noise ratio
D	It compensates for the effects of an isotropic antenna, thereby improving directivity

50. - E0A04

When evaluating a site with multiple transmitters operating at the same time, the operators and licensees of which transmitters are responsible for mitigating over-exposure situations?

Select	Answer
A	Each transmitter that produces 5 percent or more of its MPE limit at accessible locations
B	Each transmitter operating with a duty-cycle greater than 50 percent
C	Only commercial transmitters
D	Only the most powerful transmitter

Figure E5-2

Figure E7-4