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

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1. - E1A09

What is the first action you should take if your digital message forwarding station inadvertently forwards a communication that violates FCC rules?

Select	Answer
A	Notify the nearest FCC Field Engineer's office
B	Notify the originating station that the communication does not comply with FCC rules
C	Discontinue forwarding the communication as soon as you become aware of it
D	Discontinue forwarding all messages

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	A letter of intent must be filed with the National Audubon Society
C	An Environmental Assessment must be submitted to the FCC
D	A proposal must be submitted to the National Park Service

3. - E1C01

What is a remotely controlled station?

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

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 that is not able to communicate using amateur satellites
C	An amateur station within 50 km of the Earth's surface intended for communications with amateur stations by means of objects in space
D	Any amateur station on the surface of the Earth

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 submit the documents to the coordinating VEC for grading
B	They must collect and send the documents to the FCC according to instructions
C	They must submit the application document to the coordinating VEC according to the coordinating VEC instructions
D	They must collect and send the documents to the NCVEC 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	1.5 W
C	1 W
D	10 W

7. - E2A05

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

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

8. - E2B11

What is the function of the Vertical Interval Signaling (VIS) code sent as part of an SSTV transmission?

Select	Answer
A	To provide vertical synchronization
B	To identify the call sign of the station transmitting
C	To identify the SSTV mode being used
D	To lock the color burst oscillator in color SSTV images

9. - E2C04

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

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

10. - E2D12

How does JT65 improve EME communications?

Select	Answer
A	It controls the receiver to track Doppler shift
B	It can decode signals many dB below the noise floor using FEC
C	All of these choices are correct
D	It supplies signals to guide the antenna to track the Moon

11. - E2E05

Which type of digital mode does not support keyboard-to-keyboard operation?

Select	Answer
A	Winlink
B	RTTY
C	MFSK
D	PSK31

12. - E3A15

What is an electromagnetic wave?

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

13. - E3B14

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

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

14. - E3C09

How does the intensity of an X3 flare compare to that of an X2 flare?

Select	Answer
A	Four times as great
B	Twice as great
C	10 percent greater
D	50 percent greater

15. - E4A14

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

Select	Answer
A	It amplifies low level signals for more accurate counting
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 multiplies a higher frequency signal so a low-frequency counter can display the operating frequency

16. - E4B10

Which of the following describes a method to measure intermodulation distortion in an SSB transmitter?

Select	Answer
A	Modulate the transmitter with two harmonically related audio frequencies and observe the RF output with a logic analyzer
B	Modulate the transmitter with two non-harmonically related audio frequencies and observe the RF output with a spectrum analyzer
C	Modulate the transmitter with two harmonically related audio frequencies and observe the RF output with a peak reading wattmeter
D	Modulate the transmitter with two non-harmonically related radio frequencies and observe the RF output with a spectrum analyzer

17. - E4C15

What is usually the primary source of noise that is heard from an HF receiver with an antenna connected?

Select	Answer
A	Atmospheric noise
B	Induction motor noise
C	Detector noise
D	Receiver front-end noise

18. - E4D13

Which of the following can cause receiver desensitization?

Select	Answer
A	Strong adjacent channel signals
B	Audio bias adjusted too high
C	Squelch gain misadjusted
D	Audio gain adjusted too low

19. - E4E10

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

Select	Answer
A	The interfering signal may drift slowly across the HF spectrum
B	The interfering signal can be several kHz in width and usually repeats at regular intervals across a HF band
C	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
D	All of these choices are correct

20. - E5A16

What is the resonant frequency of a parallel RLC circuit if R is 33 ohms, L is 50 microhenrys and C is 10 picofarads?

Select	Answer
A	7.12 kHz
B	23.5 kHz
C	7.12 MHz
D	23.5 MHz

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

22. - E5C10

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

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

23. - E5D02

Why is it important to keep lead lengths short for components used in circuits for VHF and above?

Select	Answer
A	To avoid unwanted inductive reactance
B	To maintain component lifetime
C	All of these choices are correct
D	To increase the thermal time constant

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 for which holes are the majority carriers
D	Any FET without a channel

25. - E6B06

Which of the following is a common use of a hot-carrier diode?

Select	Answer
A	As a constant voltage reference in a power supply
B	As a variable capacitance in an automatic frequency control circuit
C	As balanced mixers in FM generation
D	As a VHF/UHF mixer or detector

26. - E6C02

What happens when the level of a comparator's input signal crosses the threshold?

Select	Answer
A	The comparator changes its output state
B	The comparator enters latch-up
C	The IC input can be damaged
D	The feedback loop becomes unstable

27. - E6D02

What is the equivalent circuit of a quartz crystal?

Select	Answer
A	Motional inductance and loss resistance in series, paralleled with motional capacitance and a capacitor representing electrode and stray capacitance
B	Motional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in series
C	Motional capacitance, motional inductance, and loss resistance in series, all in parallel with a shunt capacitor representing electrode and stray capacitance
D	Motional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in parallel

28. - E6E12

Why are high-power RF amplifier ICs and transistors sometimes mounted in ceramic packages?

Select	Answer
A	Better dissipation of heat
B	High-voltage insulating ability
C	To provide a low-pass frequency response
D	Enhanced sensitivity to light

29. - E6F05

Which describes an optical shaft encoder?

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

30. - E7A09

What logical operation is performed by an exclusive NOR gate?

Select	Answer
A	It produces logic "0" at its output only if all inputs are logic "0"
B	It produces logic "1" at its output only if all inputs are 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 if any single input is logic "1"

31. - E7B16

What is the effect of intermodulation products in a linear power amplifier?

Select	Answer
A	All of these choices are correct
B	Low efficiency
C	Creation of parasitic oscillations
D	Transmission of spurious signals

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

33. - E7D12

What is the drop-out voltage of an analog voltage regulator?

Select	Answer
A	Minimum input voltage for rated power dissipation
B	Minimum input-to-output voltage required to maintain regulation
C	Maximum amount that the output voltage may decrease at rated load
D	Maximum amount that the output voltage drops when the input voltage is varied over its specified range

34. - E7E06

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

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

35. - E7F08

What is the function of decimation with regard to digital filters?

Select	Answer
A	Converting data to binary code decimal form
B	Reducing the effective sample rate by removing samples
C	Removing unnecessary significant digits
D	Attenuating the signal

36. - E7G05

How can unwanted ringing and audio instability be prevented in a multi-section op-amp RC audio filter circuit?

Select	Answer
A	Restrict both gain and Q
B	Restrict Q but increase gain
C	Restrict gain but increase Q
D	Increase both gain and Q

37. - E7H06

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

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

38. - E8A11

What type of information can be conveyed using digital waveforms?

Select	Answer
A	All of these choices are correct
B	Video signals
C	Human speech
D	Data

39. - E8B03

What is the modulation index of an FM-phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency when the modulating frequency is 1000 Hz?

Select	Answer
A	0.3
B	3
C	3000
D	1000

40. - E8C05

What is the necessary bandwidth of a 13-WPM international Morse code transmission?

Select	Answer
A	Approximately 104 Hz
B	Approximately 26 Hz
C	Approximately 13 Hz
D	Approximately 52 Hz

41. - E8D06

Which of the following indicates likely overmodulation of an AFSK signal such as PSK or MFSK?

Select	Answer
A	High reflected power
B	Rapid signal fading
C	Harmonics on higher bands
D	Strong ALC action

42. - E9A11

Which of the following factors determines ground losses for a ground-mounted vertical antenna operating in the 3 MHz to 30 MHz range?

Select	Answer
A	Soil conductivity
B	Take-off angle
C	The standing wave ratio
D	Distance from the transmitter

43. - E9B10

What is the principle of a Method of Moments analysis?

Select	Answer
A	A wire is modeled as a series of segments, each having a uniform value of current
B	A wire is modeled as a series of points, each having a distinct location in space
C	A wire is modeled as a series of segments, each having a distinct value of voltage across it
D	A wire is modeled as a single sine-wave current generator

44. - E9C11

How is the far-field elevation pattern of a vertically polarized antenna affected by being mounted over seawater versus rocky ground?

Select	Answer
A	Both the high-angle and low-angle radiation decrease
B	The high-angle radiation increases
C	The low-angle radiation decreases
D	The low-angle radiation increases

45. - E9D12

Which of the following would provide the best RF ground for your station?

Select	Answer
A	An electrically short connection to a metal water pipe
B	An electrically short connection to 3 or 4 interconnected ground rods driven into the Earth
C	A 50 ohm resistor connected to ground
D	An electrically short connection to 3 or 4 interconnected ground rods via a series RF choke

46. - E9E13

What is a use for a Wilkinson divider?

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

47. - E9F16

Which of the following is a significant difference between foam dielectric coaxial cable and solid dielectric cable, assuming all other parameters are the same?

Select	Answer
A	Foam dielectric has lower loss per unit of length
B	All of these choices are correct
C	Foam dielectric has higher velocity factor
D	Foam dielectric has lower safe operating voltage limits

48. - E9G07

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

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

49. - E9H02

Which is generally true for low band (160 meter and 80 meter) receiving antennas?

Select	Answer
A	All of these choices are correct
B	Atmospheric noise is so high that gain over a dipole is not important
C	They must be erected at least 1/2 wavelength above the ground to attain good directivity
D	Low loss coax transmission line is essential for good performance

50. - E0A02

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

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

Figure E9-3