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

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1. - E1A04

With your transceiver displaying the carrier frequency of phone signals, you hear a DX station calling CQ on 3.601 MHz LSB. Is it legal to return the call using lower sideband on the same frequency?

Select	Answer
A	Yes, because the displayed frequency is within the 75 meter phone band segment
B	No, the sideband will extend beyond the edge of the phone band segment
C	Yes, because the DX station initiated the contact
D	No, U.S. stations are not permitted to use phone emissions below 3.610 MHz

2. - E1B07

What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?

Select	Answer
A	2.0
B	1.0
C	0.5
D	3.0

3. - E1C05

When may an automatically controlled station originate third party communications?

Select	Answer
A	When approved by the National Telecommunication and Information Administration
B	Only when transmitting RTTY or data emissions
C	When agreed upon by the sending or receiving station
D	Never

4. - E1D10

Which amateur stations are eligible to be telecommand stations?

Select	Answer
A	Any amateur station so designated by the space station licensee, subject to the privileges of the class of operator license held by the control operator
B	Any amateur station designated by NASA
C	All of these choices are correct
D	Any amateur station so designated by the ITU

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 VEC coordinating the session
C	The FCC
D	Each administering VE

6. - E1F05

Amateur stations may not transmit in which of the following frequency segments if they are located in the contiguous 48 states and north of Line A?

Select	Answer
A	53 MHz - 54 MHz
B	440 MHz - 450 MHz
C	222 MHz - 223 MHz
D	420 MHz - 430 MHz

7. - E2A14

What technology is used to track, in real time, balloons carrying amateur radio transmitters?

Select	Answer
A	Bandwidth compressed LORAN
B	Doppler shift of beacon signals
C	Radar
D	APRS

8. - E2B18

On which of the following frequencies is one likely to find FM ATV transmissions?

Select	Answer
A	14.230 MHz
B	52.525 MHz
C	29.6 MHz
D	1255 MHz

9. - E2C11

How should you generally identify your station when attempting to contact a DX station during a contest or in a pileup?

Select	Answer
A	Send only the last two letters of your call sign until you make contact
B	Send your full call sign and grid square
C	Send the call sign of the DX station three times, the words "this is", then your call sign three times
D	Send your full call sign once or twice

10. - E2D11

Which of the following data are used by the APRS network to communicate your location?

Select	Answer
A	Latitude and longitude
B	Polar coordinates
C	Time and frequency
D	Radio direction finding spectrum analysis

11. - E2E02

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

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

12. - E3A04

What do Hepburn maps predict?

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

13. - E3B09

At what time of year is Sporadic E propagation most likely to occur?

Select	Answer
A	Around the equinoxes, especially the fall equinox
B	Around the solstices, especially the winter solstice
C	Around the equinoxes, especially the spring equinox
D	Around the solstices, especially the summer solstice

14. - E3C15

What might a sudden rise in radio background noise indicate?

Select	Answer
A	A solar flare has occurred
B	Increased transequatorial propagation likely
C	A meteor ping
D	Long-path propagation is occurring

15. - E4A14

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

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

16. - E4B16

Which S parameter represents return loss or SWR?

Select	Answer
A	S11
B	S21
C	S22
D	S12

17. - E4C16

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

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

18. - E4D13

Which of the following can cause receiver desensitization?

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

19. - E4E13

What might be the cause of a loud roaring or buzzing AC line interference that comes and goes at intervals?

Select	Answer
A	A defective doorbell or doorbell transformer inside a nearby residence
B	A malfunctioning illuminated advertising display
C	All of these choices are correct
D	Arcing contacts in a thermostatically controlled device

20. - E5A05

What is the magnitude of the current at the input of a series RLC circuit as the frequency goes through resonance?

Select	Answer
A	R/L
B	Maximum
C	Minimum
D	L/R

21. - E5B09

What is the relationship between the current through a capacitor and the voltage across a capacitor?

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

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 3
B	Point 1
C	Point 8
D	Point 7

23. - E5D14

What is reactive power?

Select	Answer
A	Power consumed in wire resistance in an inductor
B	Power lost because of capacitor leakage
C	Wattless, nonproductive power
D	Power consumed in circuit Q

24. - E6A14

How does DC input impedance at the gate of a field-effect transistor compare with the DC input impedance of a bipolar transistor?

Select	Answer
A	They are both low impedance
B	An FET has high input impedance; a bipolar transistor has low input impedance
C	An FET has low input impedance; a bipolar transistor has high input impedance
D	They are both high impedance

25. - E6B07

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

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

26. - E6C02

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

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

27. - E6D16

What is the common name for a capacitor connected across a transformer secondary that is used to absorb transient voltage spikes?

Select	Answer
A	Trimmer capacitor
B	Clipper capacitor
C	Snubber capacitor
D	Feedback capacitor

28. - E6E02

Which of the following device packages is a through-hole type?

Select	Answer
A	DIP
B	SOT
C	PLCC
D	Ball grid array

29. - E6F05

Which describes an optical shaft encoder?

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

30. - E7A01

Which is a bi-stable circuit?

Select	Answer
A	An "AND" gate
B	An "OR" gate
C	A flip-flop
D	A clock

31. - E7B01

For what portion of a signal cycle does a Class AB amplifier operate?

Select	Answer
A	Less than 180 degrees
B	Exactly 180 degrees
C	More than 180 degrees but less than 360 degrees
D	The entire cycle

32. - E7C15

What is a crystal lattice filter?

Select	Answer
A	An audio filter made with four quartz crystals that resonate at 1kHz intervals
B	A filter with wide bandwidth and shallow skirts made using quartz crystals
C	A power supply filter made with interlaced quartz crystals
D	A filter with narrow bandwidth and steep skirts made using quartz crystals

33. - E7D07

What is the purpose of C2 in the circuit shown in Figure E7-3?

Select	Answer
A	To provide fixed DC bias for Q1
B	It is a brute force filter for the output
C	To self-resonate at the hum frequency
D	It bypasses hum around D1

34. - E7E01

Which of the following can be used to generate FM phone emissions?

Select	Answer
A	A reactance modulator on the final amplifier
B	A reactance modulator on the oscillator
C	A balanced modulator on the oscillator
D	A balanced modulator on the audio amplifier

35. - E7F03

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

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

36. - E7G03

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

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

37. - E7H05

How is positive feedback supplied in a Pierce oscillator?

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

38. - E8A07

What determines the PEP-to-average power ratio of a single-sideband phone signal?

Select	Answer
A	The characteristics of the modulating signal
B	The amplifier gain
C	The frequency of the modulating signal
D	The degree of carrier suppression

39. - E8B10

What describes frequency division multiplexing?

Select	Answer
A	The transmitted signal is divided into packets of information
B	Two or more information streams are merged into a baseband, which then modulates the transmitter
C	The transmitted signal jumps from band to band at a predetermined rate
D	Two or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter

40. - E8C07

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

Select	Answer
A	4.8 kHz
B	9.6 kHz
C	5.76 kHz
D	15.36 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	Ground loops
D	Bit errors in the modem

42. - E9A07

What is meant by antenna gain?

Select	Answer
A	The ratio of the signal in the forward direction to that in the opposite direction
B	The ratio of the radiated signal strength of an antenna in the direction of maximum radiation to that of a reference antenna
C	The ratio of the amount of power radiated by an antenna compared to the transmitter output power
D	The final amplifier gain minus the transmission line losses

43. - E9B06

What is the elevation angle of peak response in the antenna radiation pattern shown in Figure E9-2?

Select	Answer
A	45 degrees
B	25 degrees
C	7.5 degrees
D	75 degrees

44. - E9C02

What is the radiation pattern of two 1/4 wavelength vertical antennas spaced 1/4 wavelength apart and fed 90 degrees out of phase?

Select	Answer
A	Omni-directional
B	A figure-8 end-fire along the axis of the array
C	A figure-8 broadside to the axis of the array
D	Cardioid

45. - E9D09

What is the function of a loading coil used as part of an HF mobile antenna?

Select	Answer
A	To lower the Q
B	To cancel capacitive reactance
C	To increase the SWR bandwidth
D	To lower the losses

46. - E9E01

What system matches a higher impedance transmission line to a lower impedance antenna by connecting the line to the driven element in two places spaced a fraction of a wavelength each side of element center?

Select	Answer
A	The gamma matching system
B	The delta matching system
C	The omega matching system
D	The stub matching system

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

48. - E9G03

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

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

49. - E9H11

What characteristic of a cardioid pattern antenna is useful for direction finding?

Select	Answer
A	A very sharp peak
B	Broad band response
C	A very sharp single null
D	High-radiation angle

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	Beryllium Oxide
B	Uranium Hexafluoride
C	Mica
D	Zinc oxide

Figure E5-2

Figure E7-3

Figure E9-2