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	0.5
B	3.0
C	1.0
D	2.0

3. - E1C02

What is meant by automatic control of a station?

Select	Answer
A	A station operating with its output power controlled automatically
B	Remotely controlling a station's antenna pattern through a directional control link
C	The use of a control link between a control point and a locally controlled station
D	The use of devices and procedures for control so that the control operator does not have to be present at a control point

4. - E1D06

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

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

5. - E1E12

What must the VE team do with the application form if the examinee does not pass the exam?

Select	Answer
A	Send the application form to the FCC and inform the FCC of the grade
B	Return the application document to the examinee
C	Maintain the application form with the VEC's records
D	Destroy the application form

6. - E1F11

Which of the following best describes one of the standards that must be met by an external RF power amplifier if it is to qualify for a grant of FCC certification?

Select	Answer
A	It must produce full legal output when driven by not more than 5 watts of mean RF input power
B	It must satisfy the FCC's spurious emission standards when operated at the lesser of 1500 watts or its full output power
C	It must exhibit a gain of 0 dB or less over its full output range
D	It must be capable of external RF switching between its input and output networks

7. - E2A04

What is meant by the term mode as applied to an amateur radio satellite?

Select	Answer
A	Whether the satellite is in a polar or equatorial orbit
B	The satellite's uplink and downlink frequency bands
C	The satellite's orientation with respect to the Earth
D	The type of signals that can be relayed through the satellite

8. - E2B03

How is an interlaced scanning pattern generated in a fast-scan (NTSC) television system?

Select	Answer
A	By scanning odd numbered lines in one field and even numbered lines in the next
B	By scanning two fields simultaneously
C	By scanning each field from bottom to top
D	By scanning lines from left to right in one field and right to left in the next

9. - E2C13

What indicator is required to be used by U.S.-licensed operators when operating a station via remote control where the transmitter is located in the U.S.?

Select	Answer
A	The ARRL section of the remote station
B	/ followed by the USPS two letter abbreviation for the state in which the remote station is located
C	/R# where # is the district of the remote station
D	No additional indicator is required

10. - E2D14

What is one advantage of using JT65 coding?

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

11. - E2E11

What is the difference between direct FSK and audio FSK?

Select	Answer
A	Audio FSK can be performed anywhere in the transmit chain
B	Audio FSK has a superior frequency response
C	Direct FSK uses a DC-coupled data connection
D	Direct FSK applies the data signal to the transmitter VFO

12. - E3A05

Tropospheric propagation of microwave signals often occurs along what weather related structure?

Select	Answer
A	Sprites and jets
B	Warm and cold fronts
C	Gray-line
D	Lightning discharges

13. - E3B11

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

Select	Answer
A	Around sunrise
B	Early evening
C	Around sunset
D	Any time

14. - E3C14

Why does the radio-path horizon distance exceed the geometric horizon?

Select	Answer
A	E-region skip
B	D-region skip
C	Downward bending due to density variations in the atmosphere
D	Downward bending due to aurora refraction

15. - E4A02

Which of the following parameters would a spectrum analyzer display on the vertical and horizontal axes?

Select	Answer
A	RF amplitude and frequency
B	RF amplitude and time
C	SWR and frequency
D	SWR and time

16. - E4B16

Which S parameter represents return loss or SWR?

Select	Answer
A	S11
B	S22
C	S21
D	S12

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. - E4D12

What is the term for the reduction in receiver sensitivity caused by a strong signal near the received frequency?

Select	Answer
A	Desensitization
B	Cross-modulation interference
C	Quieting
D	Squelch gain rollback

19. - E4E14

What is one type of electrical interference that might be caused by the operation of a nearby personal computer?

Select	Answer
A	A clicking noise at intervals of a few seconds
B	A loud AC hum in the audio output of your station receiver
C	A whining type noise that continually pulses off and on
D	The appearance of unstable modulated or unmodulated signals at specific frequencies

20. - E5A01

What can cause the voltage across reactances in series to be larger than the voltage applied to them?

Select	Answer
A	Conductance
B	Resonance
C	Capacitance
D	Resistance

21. - E5B02

What is the term for the time it takes for a charged capacitor in an RC circuit to discharge to 36.8% of its initial voltage?

Select	Answer
A	One time constant
B	One discharge period
C	A discharge factor of one
D	An exponential discharge rate of one

22. - E5C08

What coordinate system is often used to display the phase angle of a circuit containing resistance, inductive and/or capacitive reactance?

Select	Answer
A	Maidenhead grid
B	Elliptical coordinates
C	Faraday grid
D	Polar coordinates

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	252 W
B	1.42 mW
C	704 W
D	355 W

24. - E6A07

Which of the following indicates that a silicon NPN junction transistor is biased on?

Select	Answer
A	Base-to-emitter voltage of approximately 0.6 to 0.7 volts
B	Base-to-emitter voltage of approximately 6 to 7 volts
C	Base-to-emitter resistance of approximately 0.6 to 0.7 ohms
D	Base-to-emitter resistance of approximately 6 to 7 ohms

25. - E6B11

What is used to control the attenuation of RF signals by a PIN diode?

Select	Answer
A	Reverse voltage larger than the RF signal
B	Capacitance of an RF coupling capacitor
C	A sub-harmonic pump signal
D	Forward DC bias current

26. - E6C04

What is the primary advantage of tri-state logic?

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

27. - E6D04

Which materials are commonly used as a slug core in a variable inductor?

Select	Answer
A	Teflon and Delrin
B	Ferrite and brass
C	Polystyrene and polyethylene
D	Cobalt and aluminum

28. - E6E03

Which of the following materials is likely to provide the highest frequency of operation when used in MMICs?

Select	Answer
A	Silicon nitride
B	Silicon
C	Silicon dioxide
D	Gallium nitride

29. - E6F12

What absorbs the energy from light falling on a photovoltaic cell?

Select	Answer
A	Electrons
B	Photons
C	Protons
D	Holes

30. - E7A04

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

Select	Answer
A	8
B	4
C	2
D	1

31. - E7B12

What type of amplifier circuit is shown in Figure E7-1?

Select	Answer
A	Common collector
B	Emitter follower
C	Common base
D	Common emitter

32. - E7C09

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

Select	Answer
A	A special filter that emphasizes image responses
B	An automatic notch filter
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. - E7D10

What is the primary reason that a high-frequency switching type high voltage power supply can be both less expensive and lighter in weight than a conventional power supply?

Select	Answer
A	The high frequency inverter design uses much smaller transformers and filter components for an equivalent power output
B	The inverter design does not require any output filtering
C	It uses a diode bridge rectifier for increased output
D	It uses a large power factor compensation capacitor to create free power from the unused portion of the AC cycle

34. - E7E07

What is meant by the term baseband in radio communications?

Select	Answer
A	The frequency components present in the modulating signal
B	The lowest frequency band that the transmitter or receiver covers
C	The basic oscillator frequency in an FM transmitter that is multiplied to increase the deviation and carrier frequency
D	The unmodulated bandwidth of the transmitted signal

35. - E7F14

Which of the following would allow a digital signal processing filter to create a sharper filter response?

Select	Answer
A	Double-precision math routines
B	Complex phasor representations
C	More taps
D	Higher data rate

36. - E7G02

What is the effect of ringing in a filter?

Select	Answer
A	A reduction in high frequency response
B	Undesired oscillations added to the desired signal
C	An echo caused by a long time delay
D	Partial cancellation of the signal over a range of frequencies

37. - E7H01

What are three oscillator circuits used in Amateur Radio equipment?

Select	Answer
A	Taft, Hartley and Pierce
B	Taft, Pierce and negative feedback
C	Pierce, Fenner and Beane
D	Colpitts, Hartley and Pierce

38. - E8A03

What type of wave does a Fourier analysis show to be made up of sine waves of a given fundamental frequency plus all of its harmonics?

Select	Answer
A	A sine wave
B	A cosine wave
C	A square wave
D	A sawtooth wave

39. - E8B02

How does the modulation index of a phase-modulated emission vary with RF carrier frequency (the modulated frequency)?

Select	Answer
A	It varies with the square root of the RF carrier frequency
B	It decreases as the RF carrier frequency increases
C	It increases as the RF carrier frequency increases
D	It does not depend on the RF carrier frequency

40. - E8C10

What is an advantage of Gray code in digital communications where symbols are transmitted as multiple bits

Select	Answer
A	It increases security
B	It has more resolution than simple binary
C	It has more possible states than simple binary
D	It facilitates error detection

41. - E8D11

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

Select	Answer
A	It is possible to transmit both upper and lower case text
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 includes built in error correction features

42. - E9A07

What is meant by antenna gain?

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

43. - E9B08

How can the approximate beam-width in a given plane of a directional antenna be determined?

Select	Answer
A	Draw two imaginary lines through the ends of the elements and measure the angle between the lines
B	Measure the ratio of the signal strengths of the radiated power lobes from the front and rear of the antenna
C	Note the two points where the signal strength of the antenna is 3 dB less than maximum and compute the angular difference
D	Measure the ratio of the signal strengths of the radiated power lobes from the front and side of the antenna

44. - E9C08

What is a folded dipole antenna?

Select	Answer
A	A type of ground-plane antenna
B	A dipole configured to provide forward gain
C	A dipole one-quarter wavelength long
D	A dipole consisting of one wavelength of wire forming a very thin loop

45. - E9D05

What is a disadvantage of using a multiband trapped antenna?

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

46. - E9E05

How must the driven element in a 3-element Yagi be tuned to use a hairpin matching system?

Select	Answer
A	The driven element resonance must be lower than the operating frequency
B	The driven element reactance must be capacitive
C	The driven element radiation resistance must be higher than the characteristic impedance of the transmission line
D	The driven element reactance must be inductive

47. - E9F05

What is the approximate physical length of a solid polyethylene dielectric coaxial transmission line that is electrically one-quarter wavelength long at 14.1 MHz?

Select	Answer
A	20 meters
B	0.2 meters
C	2.3 meters
D	3.5 meters

48. - E9G07

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

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

49. - E9H09

Which of the following describes the construction of a receiving loop antenna?

Select	Answer
A	A small coil of wire tightly wound around a toroidal ferrite core
B	One or more turns of wire wound in the shape of a large open coil
C	A vertical antenna coupled to a feed line through an inductive loop of wire
D	A large circularly polarized antenna

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

Figure E7-1

Figure E9-3