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

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1. - E1A06

Where must the carrier frequency of a CW signal be set to comply with FCC rules for 60 meter operation?

Select	Answer
A	At the highest frequency of the channel
B	On any frequency where the signal's sidebands are within the channel
C	At the center frequency of the channel
D	At the lowest frequency of the channel

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 73 dB below
B	At least 53 dB below
C	At least 43 dB below
D	At least 63 dB below

3. - E1C06

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

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

4. - E1D02

What is the amateur satellite service?

Select	Answer
A	A radio navigation service using satellites for the purpose of self training, intercommunication and technical studies carried out by amateurs
B	A radio communications service using amateur radio stations on satellites
C	A radio communications service using stations on Earth satellites for public service broadcast
D	A spacecraft launching service for amateur-built satellites

5. - E1E05

What is the minimum passing score on amateur operator license examinations?

Select	Answer
A	Minimum passing score of 77%
B	Minimum passing score of 80%
C	Minimum passing score of 70%
D	Minimum passing score of 74%

6. - E1F03

Under what circumstances may a dealer sell an external RF power amplifier capable of operation below 144 MHz if it has not been granted FCC certification?

Select	Answer
A	The equipment dealer assembled it from a kit
B	It was imported from a manufacturer in another country and was certificated by that country's government
C	It was imported from a manufacturer in a country that does not require certification of RF power amplifiers
D	It was purchased in used condition from an amateur operator and is sold to another amateur operator for use at that operator's station

7. - E2A02

What is the direction of a descending pass for an amateur satellite?

Select	Answer
A	From west to east
B	From south to north
C	From east to west
D	From north to south

8. - E2B05

Which of the following is an advantage of using vestigial sideband for standard fast- scan TV transmissions?

Select	Answer
A	The vestigial sideband carries the audio information
B	Vestigial sideband provides high frequency emphasis to sharpen the picture
C	Vestigial sideband reduces bandwidth while allowing for simple video detector circuitry
D	The vestigial sideband contains chroma information

9. - E2C03

From which of the following bands is amateur radio contesting generally excluded?

Select	Answer
A	2 m
B	30 m
C	33 cm
D	6 m

10. - E2D11

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

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

11. - E2E12

Which type of control is used by stations using the Automatic Link Enable (ALE) protocol?

Select	Answer
A	Local
B	ALE can use any type of control
C	Automatic
D	Remote

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 F1 layer
B	The D layer
C	The F2 layer
D	The E layer

13. - E3B06

Which of the following amateur bands most frequently provides long-path propagation?

Select	Answer
A	20 meters
B	80 meters
C	6 meters
D	10 meters

14. - E3C15

What might a sudden rise in radio background noise indicate?

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

15. - E4A02

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

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

16. - E4B16

Which S parameter represents return loss or SWR?

Select	Answer
A	S21
B	S11
C	S22
D	S12

17. - E4C06

A CW receiver with the AGC off has an equivalent input noise power density of -174 dBm/Hz. What would be the level of an unmodulated carrier input to this receiver that would yield an audio output SNR of 0 dB in a 400 Hz noise bandwidth?

Select	Answer
A	-148 dBm
B	-164 dBm
C	-174 dBm
D	-155 dBm

18. - E4D13

Which of the following can cause receiver desensitization?

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

19. - E4E16

What current flows equally on all conductors of an unshielded multi-conductor cable?

Select	Answer
A	Reactive current only
B	Differential-mode current
C	Common-mode current
D	Return current

20. - E5A13

What is an effect of increasing Q in a resonant circuit?

Select	Answer
A	Phase shift can become uncontrolled
B	Internal voltages and circulating currents increase
C	Parasitic effects are minimized
D	Fewer components are needed for the same performance

21. - E5B05

What happens to the magnitude of a reactance when it is converted to a susceptance?

Select	Answer
A	The sign is reversed
B	It is shifted by 90 degrees
C	It is unchanged
D	The magnitude of the susceptance is the reciprocal of the magnitude of the reactance

22. - E5C15

Which point in Figure E5-2 best represents the impedance of a series circuit consisting of a 300 ohm resistor and an 18 microhenry inductor at 3.505 MHz?

Select	Answer
A	Point 8
B	Point 1
C	Point 3
D	Point 7

23. - E5D03

What is microstrip?

Select	Answer
A	Miniature coax used for low power applications
B	Short lengths of coax mounted on printed circuit boards to minimize time delay between microwave circuits
C	Precision printed circuit conductors above a ground plane that provide constant impedance interconnects at microwave frequencies
D	Lightweight transmission line made of common zip cord

24. - E6A17

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

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

25. - E6B03

What special type of diode is capable of both amplification and oscillation?

Select	Answer
A	Zener
B	Junction
C	Tunnel
D	Point contact

26. - E6C05

What is an advantage of CMOS logic devices over TTL devices?

Select	Answer
A	Immune to damage from static discharge
B	Differential output capability
C	Lower power consumption
D	Lower distortion

27. - E6D15

What is current in the primary winding of a transformer called if no load is attached to the secondary?

Select	Answer
A	Stabilizing current
B	Direct current
C	Magnetizing current
D	Excitation current

28. - E6E04

Which is the most common input and output impedance of circuits that use MMICs?

Select	Answer
A	50 ohms
B	300 ohms
C	10 ohms
D	450 ohms

29. - E6F09

What is the efficiency of a photovoltaic cell?

Select	Answer
A	The output RF power divided by the input DC power
B	The effective payback period
C	The open-circuit voltage divided by the short-circuit current under full illumination
D	The relative fraction of light that is converted to current

30. - E7A10

What is a truth table?

Select	Answer
A	A table of logic symbols that indicate the high logic states of an op-amp
B	A diagram showing logic states when the digital device output is true
C	A table of logic symbols that indicate the logic states of an op-amp
D	A list of inputs and corresponding outputs for a digital device

31. - E7B16

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

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

32. - E7C13

What is one advantage of a Pi-matching network over an L-matching network consisting of a single inductor and a single capacitor?

Select	Answer
A	L-networks cannot perform impedance transformation
B	Pi-networks have fewer components
C	The Q of Pi-networks can be varied depending on the component values chosen
D	Pi-networks are designed for balanced input and output

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	It is generally less efficient than a linear regulator
D	The resistance of a control element is varied in direct proportion to the line voltage or load current

34. - E7E12

What is a frequency discriminator stage in a FM receiver?

Select	Answer
A	A circuit for filtering two closely adjacent signals
B	An FM generator circuit
C	An automatic band-switching circuit
D	A circuit for detecting FM signals

35. - E7F08

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

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

36. - E7G01

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

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

37. - E7H13

Which of the following is a technique for providing highly accurate and stable oscillators needed for microwave transmission and reception?

Select	Answer
A	Use a rubidium stabilized reference oscillator
B	Use a temperature-controlled high Q dielectric resonator
C	All of these choices are correct
D	Use a GPS signal reference

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 sawtooth wave
D	A square wave

39. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

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

40. - E8C03

When performing phase shift keying, why is it advantageous to shift phase precisely at the zero crossing of the RF carrier?

Select	Answer
A	This results in the least possible transmitted bandwidth for the particular mode
B	All of these choices are correct
C	It is easier to demodulate with a conventional, non-synchronous detector
D	It improves carrier suppression

41. - E8D08

What parameter might indicate that excessively high input levels are causing distortion in an AFSK signal?

Select	Answer
A	Repeat Request Rate (RRR)
B	Baud rate
C	Intermodulation Distortion (IMD)
D	Signal to noise ratio

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 final amplifier gain minus the transmission line losses
D	The ratio of the amount of power radiated by an antenna compared to the transmitter output power

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	Note the two points where the signal strength of the antenna is 3 dB less than maximum and compute the angular difference
C	Measure the ratio of the signal strengths of the radiated power lobes from the front and rear of the antenna
D	Measure the ratio of the signal strengths of the radiated power lobes from the front and side of the antenna

44. - E9C13

What is the main effect of placing a vertical antenna over an imperfect ground?

Select	Answer
A	It reduces losses in the radiating portion of the antenna
B	It reduces low-angle radiation
C	It causes increased SWR
D	It changes the impedance angle of the matching network

45. - E9D01

How does the gain of an ideal parabolic dish antenna change when the operating frequency is doubled?

Select	Answer
A	Gain increases by 6 dB
B	Gain does not change
C	Gain increases by 3 dB
D	Gain is multiplied by 0.707

46. - E9E11

What is an effective way of matching a feed line to a VHF or UHF antenna when the impedances of both the antenna and feed line are unknown?

Select	Answer
A	Connect a series-resonant LC network across the antenna feed terminals
B	Use a 50 ohm 1:1 balun between the antenna and feed line
C	Use the universal stub matching technique
D	Connect a parallel-resonant LC network across the antenna feed terminals

47. - E9F07

How does ladder line compare to small-diameter coaxial cable such as RG-58 at 50 MHz?

Select	Answer
A	Smaller reflection coefficient
B	Higher SWR
C	Lower loss
D	Lower velocity factor

48. - E9G04

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

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

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 practical for use only on VHF bands
C	It has a bidirectional pattern
D	It is non-rotatable

50. - E0A01

What is the primary function of an external earth connection or ground rod?

Select	Answer
A	Reduce RF current flow between pieces of equipment
B	Reduce RFI to telephones and home entertainment systems
C	Reduce received noise
D	Lightning protection

Figure E5-2