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

2. - E1B11

What is the permitted mean power of any spurious emission relative to the mean power of the fundamental emission from a station transmitter or external RF amplifier installed after January 1, 2003 and transmitting on a frequency below 30 MHZ?

Select	Answer
A	At least 53 dB below
B	At least 43 dB below
C	At least 73 dB below
D	At least 63 dB below

3. - E1C01

What is a remotely controlled station?

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

4. - E1D08

Which VHF amateur service bands have frequencies available for space stations?

Select	Answer
A	2 meters and 1.25 meters
B	6 meters, 2 meters, and 1.25 meters
C	2 meters
D	6 meters and 2 meters

5. - E1E08

To which of the following examinees may a VE not administer an examination?

Select	Answer
A	Employees of the VE
B	Friends of the VE
C	All of these choices are correct
D	Relatives of the VE as listed in the FCC rules

6. - E1F01

On what frequencies are spread spectrum transmissions permitted?

Select	Answer
A	Only on amateur frequencies above 144 MHz
B	Only on amateur frequencies above 222 MHz
C	Only on amateur frequencies above 50 MHz
D	Only on amateur frequencies above 420 MHz

7. - E2A13

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

Select	Answer
A	HEO
B	Geostationary
C	Geomagnetic
D	LEO

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 lines from left to right in one field and right to left in the next
C	By scanning two fields simultaneously
D	By scanning each field from bottom to top

9. - E2C04

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

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

10. - E2D13

What type of modulation is used for JT65 contacts?

Select	Answer
A	Multi-tone AFSK
B	IEEE 802.11
C	PSK
D	RTTY

11. - E2E08

Which of the following HF digital modes can be used to transfer binary files?

Select	Answer
A	Hellschreiber
B	AMTOR
C	PACTOR
D	RTTY

12. - E3A02

What characterizes libration fading of an EME signal?

Select	Answer
A	A fluttery irregular fading
B	A slow change in the pitch of the CW signal
C	A gradual loss of signal as the Sun rises
D	The returning echo is several Hertz lower in frequency than the transmitted signal

13. - E3B09

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

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

14. - E3C11

What does VOACAP software model?

Select	Answer
A	HF propagation
B	VHF radio propagation
C	AC current and impedance
D	AC voltage and impedance

15. - E4A10

Which of the following displays multiple digital signal states simultaneously?

Select	Answer
A	Modulation monitor
B	Bit error rate tester
C	Logic analyzer
D	Network analyzer

16. - E4B02

What is an advantage of using a bridge circuit to measure impedance?

Select	Answer
A	It provides an excellent match under all conditions
B	It is relatively immune to drift in the signal generator source
C	It is very precise in obtaining a signal null
D	It can display results directly in Smith chart format

17. - E4C14

What transmit frequency might generate an image response signal in a receiver tuned to 14.300 MHz and which uses a 455 kHz IF frequency?

Select	Answer
A	13.845 MHz
B	14.445 MHz
C	14.755 MHz
D	15.210 MHz

18. - E4D04

Which of the following may reduce or eliminate intermodulation interference in a repeater caused by another transmitter operating in close proximity?

Select	Answer
A	A properly terminated circulator at the output of the transmitter
B	A Class D final amplifier
C	A band-pass filter in the feed line between the transmitter and receiver
D	A Class C final amplifier

19. - E4E02

Which of the following types of receiver noise can often be reduced with a DSP noise filter?

Select	Answer
A	Broadband white noise
B	Power line noise
C	Ignition noise
D	All of these choices are correct

20. - E5A08

What is the phase relationship between the current through and the voltage across a series resonant circuit at resonance?

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

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 180 degrees out of phase
B	Voltage and current are in phase
C	Voltage leads current by 90 degrees
D	Current leads voltage 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	The sum of the reactive and resistive components
B	The difference between the resistive and reactive components
C	Reactive component
D	Resistive component

23. - E5D15

What is the power factor of an R-L circuit having a 45 degree phase angle between the voltage and the current?

Select	Answer
A	0.707
B	0.866
C	1.0
D	0.5

24. - E6A17

What are the names of the three terminals of a field-effect transistor?

Select	Answer
A	Emitter, base, collector
B	Gate 1, gate 2, drain
C	Emitter, base 1, base 2
D	Gate, drain, source

25. - E6B06

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

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

26. - E6C13

Which of the following is an advantage of BiCMOS logic?

Select	Answer
A	Its simplicity results in much less expensive devices than standard CMOS
B	It is totally immune to electrostatic damage
C	All of these choices are correct
D	It has the high input impedance of CMOS and the low output impedance of bipolar transistors

27. - E6D05

What is one reason for using ferrite cores rather than powdered-iron in an inductor?

Select	Answer
A	Ferrite toroids generally require fewer turns to produce a given inductance value
B	Ferrite toroids generally have lower initial permeability
C	Ferrite toroids are easier to use with surface mount technology
D	Ferrite toroids generally have better temperature stability

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	Gallium nitride
C	Silicon
D	Silicon dioxide

29. - E6F11

What is the approximate open-circuit voltage produced by a fully-illuminated silicon photovoltaic cell?

Select	Answer
A	1.5 V
B	0.5 V
C	12 V
D	0.1 V

30. - E7A03

Which of the following can divide the frequency of a pulse train by 2?

Select	Answer
A	A multiplexer
B	A flip-flop
C	An XOR gate
D	An OR gate

31. - E7B11

In Figure E7-1, what is the purpose of R3?

Select	Answer
A	Emitter bypass
B	Fixed bias
C	Self bias
D	Output load resistor

32. - E7C14

Which mode is most affected by non-linear phase response in a receiver IF filter?

Select	Answer
A	Meteor scatter
B	Video
C	Digital
D	Single-Sideband voice

33. - E7D02

What is one characteristic of a switching electronic voltage regulator?

Select	Answer
A	It gives a ramp voltage at its output
B	The controlled device's duty cycle is changed to produce a constant average output voltage
C	The resistance of a control element is varied in direct proportion to the line voltage or load current
D	It is generally less efficient than a linear regulator

34. - E7E06

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

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

35. - E7F09

Why is an anti-aliasing digital filter required in a digital decimator?

Select	Answer
A	It notches out the sampling frequency to avoid sampling errors
B	It removes high-frequency signal components which would otherwise be reproduced as lower frequency components
C	It removes low frequency signal components to eliminate the need for DC restoration
D	It peaks the response of the decimator, improving bandwidth

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	47
D	0.21

37. - E7H06

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

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

38. - E8A02

What type of wave has a rise time significantly faster than its fall time (or vice versa)?

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

39. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

Select	Answer
A	A bandwidth compression technique using Fourier transforms
B	A digital modulation technique using subcarriers at frequencies chosen to avoid intersymbol interference
C	A digital mode for narrow band, slow speed transmissions
D	A frequency modulation technique which uses non-harmonically related frequencies

40. - E8C02

What is the definition of symbol rate in a digital transmission?

Select	Answer
A	The number of control characters in a message packet
B	The rate at which the waveform of a transmitted signal changes to convey information
C	The number of characters carried per second by the station-to-station link
D	The duration of each bit in a message sent over the air

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. - E9A05

What is included in the total resistance of an antenna system?

Select	Answer
A	Radiation resistance plus space impedance
B	Radiation resistance plus transmission resistance
C	Transmission-line resistance plus radiation resistance
D	Radiation resistance plus ohmic resistance

43. - E9B13

What does the abbreviation NEC stand for when applied to antenna modeling programs?

Select	Answer
A	Next Element Comparison
B	National Electrical Code
C	Numeric Electrical Computation
D	Numerical Electromagnetic Code

44. - E9C04

What happens to the radiation pattern of an unterminated long wire antenna as the wire length is increased?

Select	Answer
A	The lobes align more in the direction of the wire
B	The front-to-back ratio decreases
C	The vertical angle increases
D	The lobes become more perpendicular to the wire

45. - E9D04

Why should an HF mobile antenna loading coil have a high ratio of reactance to resistance?

Select	Answer
A	To maximize losses
B	To minimize the Q
C	To swamp out harmonics
D	To minimize losses

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	Connect 1/2 wavelength shorted stub of 75 ohm cable in parallel with the 50 ohm cable where it attaches to the antenna
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	Insert a 1/2 wavelength piece of 300 ohm twin-lead in series between the antenna terminals and the 50 ohm feed cable

47. - E9F08

What is the term for the ratio of the actual speed at which a signal travels through a transmission line to the speed of light in a vacuum?

Select	Answer
A	Characteristic impedance
B	Standing wave ratio
C	Surge impedance
D	Velocity factor

48. - E9G06

On the Smith chart shown in Figure E9-3, what is the name for the large outer circle on which the reactance arcs terminate?

Select	Answer
A	Impedance axis
B	Reactance axis
C	Prime axis
D	Polar axis

49. - E9H05

What is the main drawback of a wire-loop antenna for direction finding?

Select	Answer
A	It receives equally well in all directions
B	It is non-rotatable
C	It has a bidirectional pattern
D	It is practical for use only on VHF bands

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

Figure E7-1

Figure E7-4

Figure E9-3