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

2. - E1B08

What limitations may the FCC place on an amateur station if its signal causes interference to domestic broadcast reception, assuming that the receivers involved are of good engineering design?

Select	Answer
A	The amateur station must cease operation on all frequencies below 30 MHz
B	The amateur station must avoid transmitting during certain hours on frequencies that cause the interference
C	The amateur station must cease operation
D	The amateur station must cease operation on all frequencies above 30 MHz

3. - E1C06

Which of the following statements concerning remotely controlled amateur stations is true?

Select	Answer
A	A control operator must be present at the control point
B	Repeater and auxiliary stations may not be remotely controlled
C	A control operator need not be present at the control point
D	Only Extra Class operators may be the control operator of a remote station

4. - E1D07

Which amateur service HF bands have frequencies authorized for space stations?

Select	Answer
A	Only the 40 m, 20 m, 17 m, 15 m and 10 m bands
B	Only the 40 m, 30 m, 20 m, 15 m, 12 m and 10 m bands
C	Only the 40 m, 20 m, 17 m, 15 m, 12 m and 10 m bands
D	All HF bands

5. - E1E12

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

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

6. - E1F07

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

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

7. - E2A13

What type of satellite appears to stay in one position in the sky?

Select	Answer
A	LEO
B	Geomagnetic
C	HEO
D	Geostationary

8. - E2B16

Which is a video standard used by North American Fast Scan ATV stations?

Select	Answer
A	DRM
B	Scottie
C	PAL
D	NTSC

9. - E2C09

What type of equipment is commonly used to implement a ham radio mesh network?

Select	Answer
A	A 2 meter VHF transceiver with a 1200 baud modem
B	A 440 MHz transceiver with a 9600 baud modem
C	An optical cable connection between the USB ports of 2 separate computers
D	A standard wireless router running custom software

10. - E2D03

Which of the following digital modes is especially useful for EME communications?

Select	Answer
A	FSK441
B	JT65
C	PACTOR III
D	Olivia

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

12. - E3A08

When a meteor strikes the Earth's atmosphere, a cylindrical region of free electrons is formed at what layer of the ionosphere?

Select	Answer
A	The E layer
B	The F2 layer
C	The F1 layer
D	The D layer

13. - E3B09

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

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

14. - E3C02

What is indicated by a rising A or K index?

Select	Answer
A	Increasing disruption of the geomagnetic field
B	An increase in the critical frequency
C	Decreasing disruption of the geomagnetic field
D	Higher levels of solar UV radiation

15. - E4A04

What determines the upper frequency limit for a computer soundcard-based oscilloscope program?

Select	Answer
A	Amount of memory on the soundcard
B	Analog-to-digital conversion speed of the soundcard
C	All of these choices are correct
D	Q of the interface of the interface circuit

16. - E4B13

Which S parameter is equivalent to forward gain?

Select	Answer
A	S21
B	S22
C	S11
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	Distortion
B	Overload
C	Excess output level
D	Loss of sensitivity

18. - E4D05

What transmitter frequencies would cause an intermodulation-product signal in a receiver tuned to 146.70 MHz when a nearby station transmits on 146.52 MHz?

Select	Answer
A	146.10 MHz and 147.30 MHz
B	173.35 MHz and 139.40 MHz
C	146.34 MHz and 146.61 MHz
D	146.88 MHz and 146.34 MHz

19. - E4E04

How can conducted and radiated noise caused by an automobile alternator be suppressed?

Select	Answer
A	By installing filter capacitors in series with the DC power lead and a blocking capacitor in the field lead
B	By installing a noise suppression resistor and a blocking capacitor in both leads
C	By connecting the radio's power leads directly to the battery and by installing coaxial capacitors in line with the alternator leads
D	By installing a high-pass filter in series with the radio's power lead and a low-pass filter in parallel with the field lead

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

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

22. - E5C14

Which point on Figure E5-2 best represents the impedance of a series circuit consisting of a 400 ohm resistor and a 38 picofarad capacitor at 14 MHz?

Select	Answer
A	Point 2
B	Point 5
C	Point 4
D	Point 6

23. - E5D16

What is the power factor of an R-L circuit having a 30 degree phase angle between the voltage and the current?

Select	Answer
A	0.577
B	0.866
C	0.5
D	1.73

24. - E6A16

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

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

25. - E6B02

What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

Select	Answer
A	Much higher reverse voltage breakdown
B	Less forward voltage drop
C	Enhanced carrier retention time
D	Controlled reverse avalanche voltage

26. - E6C01

What is the function of hysteresis in a comparator?

Select	Answer
A	To increase the sensitivity
B	To prevent input noise from causing unstable output signals
C	To cause the output to change states continually
D	To allow the comparator to be used with AC input signal

27. - E6D09

What devices are commonly used as VHF and UHF parasitic suppressors at the input and output terminals of a transistor HF amplifier?

Select	Answer
A	Electrolytic capacitors
B	Ferrite beads
C	Butterworth filters
D	Steel-core toroids

28. - E6E03

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

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

29. - E6F12

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

Select	Answer
A	Holes
B	Photons
C	Protons
D	Electrons

30. - E7A07

What logical operation does a NAND gate perform?

Select	Answer
A	It produces logic "1" at its output only when all inputs are logic "1"
B	It produces logic "0" at its output if some but not all inputs are logic "1"
C	It produces logic "0" at its output only when all inputs are logic "1"
D	It produces logic "0" at its output only when all inputs are logic "0"

31. - E7B10

In Figure E7-1, what is the purpose of R1 and R2?

Select	Answer
A	Feedback
B	Fixed bias
C	Self bias
D	Load resistors

32. - E7C06

What are the distinguishing features of an elliptical filter?

Select	Answer
A	Gradual passband rolloff with minimal stop band ripple
B	Extremely sharp cutoff with one or more notches in the stop band
C	Extremely flat response over its pass band with gradually rounded stop band corners
D	Gradual passband rolloff with extreme stop band ripple

33. - E7D07

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

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

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

35. - E7F16

How might the sampling rate of an existing digital signal be adjusted by a factor of 3/4?

Select	Answer
A	Add 3 to each input value and subtract 4 from each output value
B	Multiply each sample value by a factor of 3/4
C	Change the gain by a factor of 3/4
D	Interpolate by a factor of three, then decimate by a factor of four

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	47
C	94
D	0.21

37. - E7H08

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

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

38. - E8A01

What is the name of the process that shows that a square wave is made up of a sine wave plus all of its odd harmonics?

Select	Answer
A	Differential analysis
B	Numerical analysis
C	Fourier analysis
D	Vector analysis

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 does not depend on the RF carrier frequency
C	It increases as the RF carrier frequency increases
D	It decreases as the RF carrier frequency increases

40. - E8C06

What is the necessary bandwidth of a 170-hertz shift, 300-baud ASCII transmission?

Select	Answer
A	0.1 Hz
B	1.0 kHz
C	0.3 kHz
D	0.5 kHz

41. - E8D05

What is the most common method of reducing key clicks?

Select	Answer
A	Reduce keying waveform rise and fall times
B	High-pass filters at the transmitter output
C	Increase keying waveform rise and fall times
D	Low-pass filters at the transmitter output

42. - E9A03

Why would one need to know the feed point impedance of an antenna?

Select	Answer
A	To measure the near-field radiation density from a transmitting antenna
B	To calculate the front-to-side ratio of the antenna
C	To calculate the front-to-back ratio of the antenna
D	To match impedances in order to minimize standing wave ratio on the transmission line

43. - E9B04

What may occur when a directional antenna is operated at different frequencies within the band for which it was designed?

Select	Answer
A	Feed point impedance may become negative
B	The E-field and H-field patterns may reverse
C	Element spacing limits could be exceeded
D	The gain may change depending on frequency

44. - E9C09

What is a G5RV antenna?

Select	Answer
A	A multi-band dipole antenna fed with coax and a balun through a selected length of open wire transmission line
B	A phased array antenna consisting of multiple loops
C	A wide band dipole using shorted coaxial cable for the radiating elements and fed with a 4:1 balun
D	A multi-band trap antenna

45. - E9D06

What happens to the bandwidth of an antenna as it is shortened through the use of loading coils?

Select	Answer
A	It is increased
B	It is decreased
C	It becomes flat
D	No change occurs

46. - E9E10

Which of these choices is an effective way to match an antenna with a 100 ohm feed point impedance to a 50 ohm coaxial cable feed line?

Select	Answer
A	Insert a 1/2 wavelength piece of 300 ohm twin-lead in series between the antenna terminals and the 50 ohm feed cable
B	Insert a 1/4-wavelength piece of 75 ohm coaxial cable transmission line in series between the antenna terminals and the 50 ohm feed cable
C	Connect a 1/4-wavelength open stub of 300 ohm twin-lead in parallel with the coaxial feed line where it connects to the antenna
D	Connect 1/2 wavelength shorted stub of 75 ohm cable in parallel with the 50 ohm cable where it attaches to the antenna

47. - E9F13

What impedance does a 1/4 wavelength transmission line present to a generator when the line is shorted at the far end?

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

48. - E9G04

What are the two families of circles and arcs that make up a Smith chart?

Select	Answer
A	Reactance and voltage
B	Voltage and impedance
C	Resistance and voltage
D	Resistance and reactance

49. - E9H06

What is the triangulation method of direction finding?

Select	Answer
A	Antenna headings from several different receiving locations are used to locate the signal source
B	A fixed receiving station plots three headings to the signal source
C	A fixed receiving station uses three different antennas to plot the location of the signal source
D	The geometric angles of sky waves from the source are used to determine its position

50. - E0A10

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

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

Figure E5-2

Figure E7-1

Figure E7-3

Figure E7-4