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

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1. - E1A10

If an amateur station is installed aboard a ship or aircraft, what condition must be met before the station is operated?

Select	Answer
A	The amateur station operator must agree not to transmit when the main radio of the ship or aircraft is in use
B	The amateur operator must have an FCC Marine or Aircraft endorsement on his or her amateur license
C	The amateur station must have a power supply that is completely independent of the main ship or aircraft power supply
D	Its operation must be approved by the master of the ship or the pilot in command of the aircraft

2. - E1B10

What frequencies are authorized to an amateur station operating under RACES rules?

Select	Answer
A	Specific local government channels
B	Specific segments in the amateur service MF, HF, VHF and UHF bands
C	Military Auxiliary Radio System (MARS) channels
D	All amateur service frequencies authorized to the control operator

3. - E1C02

What is meant by automatic control of a station?

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

4. - E1D10

Which amateur stations are eligible to be telecommand stations?

Select	Answer
A	All of these choices are correct
B	Any amateur station so designated by the ITU
C	Any amateur station designated by NASA
D	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

5. - E1E13

Which of these choices is an acceptable method for monitoring the applicants if a VEC opts to conduct an exam session remotely?

Select	Answer
A	The exam proctor observes the applicants and reports any violations
B	Have each applicant sign an affidavit stating that all session rules were followed
C	Use a real-time video link and the Internet to connect the exam session to the observing VEs
D	Record the exam session on video tape for later review by the VE team

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. - E2A05

What do the letters in a satellite's mode designator specify?

Select	Answer
A	The polarization of uplink and downlink signals
B	The location of the ground control station
C	The uplink and downlink frequency ranges
D	Power limits for uplink and downlink transmissions

8. - E2B15

What signals SSTV receiving equipment to begin a new picture line?

Select	Answer
A	A two-tone signal
B	Elapsed time
C	Specific tone frequencies
D	Specific tone amplitudes

9. - E2C06

During a VHF/UHF contest, in which band segment would you expect to find the highest level of activity?

Select	Answer
A	At the top of each band, usually in a segment reserved for contests
B	In the middle of each band, usually on the national calling frequency
C	In the middle of the band, usually 25 kHz above the national calling frequency
D	In the weak signal segment of the band, with most of the activity near the calling frequency

10. - E2D14

What is one advantage of using JT65 coding?

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

11. - E2E06

What is the most common data rate used for HF packet?

Select	Answer
A	300 baud
B	48 baud
C	110 baud
D	1200 baud

12. - E3A15

What is an electromagnetic wave?

Select	Answer
A	A wave consisting of two electric fields at parallel right angles to each other
B	A wave of alternating current, in the core of an electromagnet
C	A wave consisting of two magnetic fields at right angles to each other
D	A wave consisting of an electric field and a magnetic field oscillating at right angles to each other

13. - E3B10

What is the cause of gray-line propagation?

Select	Answer
A	At midday, the Sun super heats the ionosphere causing increased refraction of radio waves
B	At twilight and sunrise, D-layer absorption is low while E-layer and F-layer propagation remains high
C	In darkness, solar absorption drops greatly while atmospheric ionization remains steady
D	At mid-afternoon, the Sun heats the ionosphere decreasing radio wave refraction and the MUF

14. - E3C02

What is indicated by a rising A or K index?

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

15. - E4A01

Which of the following parameter determines the bandwidth of a digital or computer-based oscilloscope?

Select	Answer
A	Sampling rate
B	Input impedance
C	Input capacitance
D	Sample resolution

16. - E4B16

Which S parameter represents return loss or SWR?

Select	Answer
A	S22
B	S12
C	S21
D	S11

17. - E4C15

What is usually the primary source of noise that is heard from an HF receiver with an antenna connected?

Select	Answer
A	Detector noise
B	Atmospheric noise
C	Receiver front-end noise
D	Induction motor noise

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. - E4E11

Which is the most likely cause if you are hearing combinations of local AM broadcast signals within one or more of the MF or HF ham bands?

Select	Answer
A	You are receiving sky wave signals from a distant station
B	Your station receiver IF amplifier stage is defective
C	The broadcast station is transmitting an over-modulated signal
D	Nearby corroded metal joints are mixing and re-radiating the broadcast signals

20. - E5A14

What is the resonant frequency of a series RLC circuit if R is 22 ohms, L is 50 microhenrys and C is 40 picofarads?

Select	Answer
A	3.56 MHz
B	22.36 MHz
C	1.78 MHz
D	44.72 MHz

21. - E5B04

What is the time constant of a circuit having two 220 microfarad capacitors and two 1 megohm resistors, all in parallel?

Select	Answer
A	440 seconds
B	220 seconds
C	55 seconds
D	110 seconds

22. - E5C09

When using rectangular coordinates to graph the impedance of a circuit, what does the horizontal axis represent?

Select	Answer
A	Resistive component
B	Reactive component
C	The sum of the reactive and resistive components
D	The difference between the resistive and reactive components

23. - E5D11

What is the power factor of an R-L circuit having a 60 degree phase angle between the voltage and the current?

Select	Answer
A	1.414
B	1.73
C	0.866
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, drain, source
C	Gate 1, gate 2, drain
D	Emitter, base 1, base 2

25. - E6B11

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

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

26. - E6C13

Which of the following is an advantage of BiCMOS logic?

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

27. - E6D14

Which type of slug material decreases inductance when inserted into a coil?

Select	Answer
A	Brass
B	Ceramic
C	Powdered-iron
D	Ferrite

28. - E6E04

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

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

29. - E6F04

What is the photovoltaic effect?

Select	Answer
A	The conversion of electrical energy to mechanical energy
B	The conversion of light to electrical energy
C	The conversion of voltage to current when exposed to light
D	The tendency of a battery to discharge when used outside

30. - E7A04

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

Select	Answer
A	4
B	2
C	1
D	8

31. - E7B11

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

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

32. - E7C03

What advantage does a Pi-L-network have over a regular Pi-network for impedance matching between the final amplifier of a vacuum-tube transmitter and an antenna?

Select	Answer
A	Greater harmonic suppression
B	Greater transformation range
C	Lower losses
D	Higher efficiency

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	To self-resonate at the hum frequency
C	It bypasses hum around D1
D	To provide fixed DC bias for Q1

34. - E7E04

What is one way a single-sideband phone signal can be generated?

Select	Answer
A	By driving a product detector with a DSB signal
B	By using a reactance modulator followed by a mixer
C	By using a balanced modulator followed by a filter
D	By using a loop modulator followed by a mixer

35. - E7F02

What kind of digital signal processing audio filter is used to remove unwanted noise from a received SSB signal?

Select	Answer
A	A phase-inverting filter
B	An adaptive filter
C	A crystal-lattice filter
D	A Hilbert-transform filter

36. - E7G11

What absolute voltage gain can be expected from the circuit in Figure E7-4 when R1 is 3300 ohms and RF is 47 kilohms?

Select	Answer
A	28
B	14
C	7
D	0.07

37. - E7H03

How is positive feedback supplied in a Hartley oscillator?

Select	Answer
A	Through a capacitive divider
B	Through link coupling
C	Through a neutralizing capacitor
D	Through a tapped coil

38. - E8A05

What would be the most accurate way of measuring the RMS voltage of a complex waveform?

Select	Answer
A	By using a grid dip meter
B	By measuring the voltage with a D'Arsonval meter
C	By measuring the heating effect in a known resistor
D	By using an absorption wave meter

39. - E8B06

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz when the maximum modulation frequency is 3.5 kHz?

Select	Answer
A	47
B	2.14
C	0.47
D	0.214

40. - E8C10

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

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

41. - E8D01

Why are received spread spectrum signals resistant to interference?

Select	Answer
A	If interference is detected by the receiver it will signal the transmitter to change frequencies
B	The high power used by a spread spectrum transmitter keeps its signal from being easily overpowered
C	The receiver is always equipped with a digital blanker
D	Signals not using the spread spectrum algorithm are suppressed in the receiver

42. - E9A04

Which of the following factors may affect the feed point impedance of an antenna?

Select	Answer
A	Sunspot activity and time of day
B	Antenna height, conductor length/diameter ratio and location of nearby conductive objects
C	The settings of an antenna tuner at the transmitter
D	Transmission-line length

43. - E9B14

What type of information can be obtained by submitting the details of a proposed new antenna to a modeling program?

Select	Answer
A	Antenna gain
B	Polar plots of the far field elevation and azimuth patterns
C	All of these choices are correct
D	SWR vs frequency charts

44. - E9C14

How does the performance of a horizontally polarized antenna mounted on the side of a hill compare with the same antenna mounted on flat ground?

Select	Answer
A	The main lobe takeoff angle decreases in the downhill direction
B	The main lobe takeoff angle increases in the downhill direction
C	The horizontal beam width decreases in the downhill direction
D	The horizontal beam width increases in the uphill direction

45. - E9D11

Which of the following types of conductors would be best for minimizing losses in a station's RF ground system?

Select	Answer
A	A cable with six or seven 18 gauge conductors in parallel
B	A wide flat copper strap
C	A single 12 gauge or 10 gauge stainless steel wire
D	A resistive wire, such as spark plug wire

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

47. - E9F14

What impedance does a 1/2 wavelength transmission line present to a generator when the line is shorted at the far end?

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

48. - E9G02

What type of coordinate system is used in a Smith chart?

Select	Answer
A	Voltage lines and current chords
B	Resistance circles and reactance arcs
C	Voltage circles and current arcs
D	Resistance lines and reactance chords

49. - E9H02

Which is generally true for low band (160 meter and 80 meter) receiving antennas?

Select	Answer
A	Low loss coax transmission line is essential for good performance
B	They must be erected at least 1/2 wavelength above the ground to attain good directivity
C	Atmospheric noise is so high that gain over a dipole is not important
D	All of these choices are correct

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 E7-3

Figure E7-4