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

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1. - E1A05

What is the maximum power output permitted on the 60 meter band?

Select	Answer
A	100 watts PEP effective radiated power relative to an isotropic radiator
B	50 watts PEP effective radiated power relative to an isotropic radiator
C	50 watts PEP effective radiated power relative to a dipole
D	100 watts PEP effective radiated power relative to the gain of a half-wave dipole

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. - E1C05

When may an automatically controlled station originate third party communications?

Select	Answer
A	Never
B	When agreed upon by the sending or receiving station
C	Only when transmitting RTTY or data emissions
D	When approved by the National Telecommunication and Information Administration

4. - E1D03

What is a telecommand station in the amateur satellite service?

Select	Answer
A	An amateur station located on the Earth's surface for communication with other Earth stations by means of Earth satellites
B	An amateur station that transmits communications to initiate, modify or terminate functions of a space station
C	An amateur station that transmits telemetry consisting of measurements of upper atmosphere
D	An amateur station located more than 50 km above the Earth's surface

5. - E1E09

What may be the penalty for a VE who fraudulently administers or certifies an examination?

Select	Answer
A	Revocation of the VE's amateur station license grant and the suspension of the VE's amateur operator license grant
B	A sentence of up to one year in prison
C	All of these choices are correct
D	A fine of up to $1000 per occurrence

6. - E1F01

On what frequencies are spread spectrum transmissions permitted?

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

7. - E2A06

On what band would a satellite receive signals if it were operating in mode U/V?

Select	Answer
A	29.5 MHz - 29.7 MHz
B	435 MHz - 438 MHz
C	50.0 MHz - 50.2 MHz
D	144 MHz - 146 MHz

8. - E2B04

What is blanking in a video signal?

Select	Answer
A	Synchronization of the horizontal and vertical sync pulses
B	Turning off the scanning beam while it is traveling from right to left or from bottom to top
C	Turning off the scanning beam at the conclusion of a transmission
D	Transmitting a black and white test pattern

9. - E2C10

Why might a DX station state that they are listening on another frequency?

Select	Answer
A	All of these choices are correct
B	To improve operating efficiency by reducing interference
C	To separate the calling stations from the DX station
D	Because the DX station may be transmitting on a frequency that is prohibited to some responding stations

10. - E2D06

Which of the following describes a method of establishing EME contacts?

Select	Answer
A	Judging optimum transmission times by monitoring beacons reflected from the Moon
B	Storing and forwarding digital messages
C	High speed CW identification to avoid fading
D	Time synchronous transmissions alternately from each station

11. - E2E04

What is indicated when one of the ellipses in an FSK crossed-ellipse display suddenly disappears?

Select	Answer
A	One of the signal filters is saturated
B	The mark and space signal have been inverted
C	The receiver has drifted 5 kHz from the desired receive frequency
D	Selective fading has occurred

12. - E3A09

Which of the following frequency range is most suited for meteor scatter communications?

Select	Answer
A	28 MHz - 148 MHz
B	220 MHz - 450 MHz
C	10 MHz - 14 MHz
D	1.8 MHz - 1.9 MHz

13. - E3B12

What is the primary characteristic of chordal hop propagation?

Select	Answer
A	Successive ionospheric reflections without an intermediate reflection from the ground
B	Propagation across the geomagnetic equator
C	Propagation away from the great circle bearing between stations
D	Signals reflected back toward the transmitting station

14. - E3C04

What does the value of Bz (B sub Z) represent?

Select	Answer
A	Direction and strength of the interplanetary magnetic field
B	Duration of long-delayed echoes
C	Critical frequency for vertical transmissions
D	Geomagnetic field stability

15. - E4A03

Which of the following test instrument is used to display spurious signals and/or intermodulation distortion products in an SSB transmitter?

Select	Answer
A	A time-domain reflectometer
B	A spectrum analyzer
C	A logic analyzer
D	A wattmeter

16. - E4B11

How should an antenna analyzer be connected when measuring antenna resonance and feed point impedance?

Select	Answer
A	Connect the antenna feed line directly to the analyzer's connector
B	Loosely couple the analyzer near the antenna base
C	Connect the analyzer via a high-impedance transformer to the antenna
D	Loosely couple the antenna and a dummy load to the analyzer

17. - E4C15

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

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

18. - E4D07

Which describes the most significant effect of an off-frequency signal when it is causing cross-modulation interference to a desired signal?

Select	Answer
A	A reduction in apparent signal strength
B	The desired signal can no longer be heard
C	The off-frequency unwanted signal is heard in addition to the desired signal
D	A large increase in background noise

19. - E4E06

What is a major cause of atmospheric static?

Select	Answer
A	Thunderstorms
B	Geomagnetic storms
C	Meteor showers
D	Solar radio frequency emissions

20. - E5A16

What is the resonant frequency of a parallel RLC circuit if R is 33 ohms, L is 50 microhenrys and C is 10 picofarads?

Select	Answer
A	23.5 kHz
B	23.5 MHz
C	7.12 kHz
D	7.12 MHz

21. - E5B07

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 500 ohms, R is 1 kilohm, and XL is 250 ohms?

Select	Answer
A	68.2 degrees with the voltage leading the current
B	14.0 degrees with the voltage lagging the current
C	68.2 degrees with the voltage lagging the current
D	14.0 degrees with the voltage leading the current

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	Resistive component
C	The difference between the resistive and reactive components
D	Reactive component

23. - E5D04

Why are short connections necessary at microwave frequencies?

Select	Answer
A	To reduce phase shift along the connection
B	To reduce noise figure
C	Because of ground reflections
D	To increase neutralizing resistance

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. - E6B08

Which of the following describes a type of semiconductor diode?

Select	Answer
A	Metal-semiconductor junction
B	CMOS-field effect
C	Electrolytic rectifier
D	Thermionic emission diode

26. - E6C06

Why do CMOS digital integrated circuits have high immunity to noise on the input signal or power supply?

Select	Answer
A	Input signals are stronger
B	The input switching threshold is about one-half the power supply voltage
C	The input switching threshold is about two times the power supply voltage
D	Larger bypass capacitors are used in CMOS circuit design

27. - E6D08

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

Select	Answer
A	Powdered-iron cores use smaller diameter wire for the same inductance
B	Powdered-iron cores generally have greater initial permeability
C	Powdered-iron cores generally require fewer turns to produce a given inductance
D	Powdered-iron cores generally maintain their characteristics at higher currents

28. - E6E01

Which of the following is true of a charge-coupled device (CCD)?

Select	Answer
A	It is a CMOS analog-to-digital converter
B	Its phase shift changes rapidly with frequency
C	It samples an analog signal and passes it in stages from the input to the output
D	It is used in a battery charger circuit

29. - E6F03

What is the most common configuration of an optoisolator or optocoupler?

Select	Answer
A	An amplitude modulated helium-neon laser
B	A frequency modulated helium-neon laser
C	A lens and a photomultiplier
D	An LED and a phototransistor

30. - E7A12

What type of logic defines "0" as a high voltage?

Select	Answer
A	Positive Logic
B	Negative logic
C	Assertive Logic
D	Reverse Logic

31. - E7B15

What is one way to prevent thermal runaway in a bipolar transistor amplifier?

Select	Answer
A	Neutralization
B	Use a resistor in series with the emitter
C	All of these choices are correct
D	Select transistors with high beta

32. - E7C02

Which of the following is a property of a T-network with series capacitors and a parallel shunt inductor?

Select	Answer
A	It is a low-pass filter
B	It is a notch filter
C	It is a band-pass filter
D	It is a high-pass filter

33. - E7D13

What is the equation for calculating power dissipation by a series connected linear voltage regulator?

Select	Answer
A	Input voltage multiplied by input current
B	Voltage difference from input to output multiplied by output current
C	Output voltage multiplied by output current
D	Input voltage divided by output current

34. - E7E08

What are the principal frequencies that appear at the output of a mixer circuit?

Select	Answer
A	1.414 and 0.707 times the input frequency
B	Two and four times the original frequency
C	The two input frequencies along with their sum and difference frequencies
D	The sum, difference and square root of the input frequencies

35. - E7F05

How frequently must an analog signal be sampled by an analog-to-digital converter so that the signal can be accurately reproduced?

Select	Answer
A	At half the rate of the highest frequency component of the signal
B	At four times the rate of the highest frequency component of the signal
C	At twice the rate of the highest frequency component of the signal
D	At the same rate as the highest frequency component of the signal

36. - E7G01

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

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

37. - E7H05

How is positive feedback supplied in a Pierce oscillator?

Select	Answer
A	Through a quartz crystal
B	Through link coupling
C	Through a neutralizing capacitor
D	Through a tapped coil

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 sawtooth wave
C	A square wave
D	A cosine wave

39. - E8B01

What is the term for the ratio between the frequency deviation of an RF carrier wave and the modulating frequency of its corresponding FM-phone signal?

Select	Answer
A	Quieting index
B	FM compressibility
C	Percentage of modulation
D	Modulation index

40. - E8C09

Which is the name of a digital code where each preceding or following character changes by only one bit?

Select	Answer
A	Gray code
B	Extended Binary Coded Decimal Interchange Code
C	Excess 3 code
D	Binary Coded Decimal Code

41. - E8D10

What are some of the differences between the Baudot digital code and ASCII?

Select	Answer
A	Baudot uses 6 data bits per character, ASCII uses 7 or 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes
B	Baudot uses 5 data bits per character, ASCII uses 7 or 8; Baudot uses 2 characters as letters/figures shift codes, ASCII has no letters/figures shift code
C	Baudot uses 7 data bits per character, ASCII uses 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes
D	Baudot uses 4 data bits per character, ASCII uses 7 or 8; Baudot uses 1 character as a letters/figures shift code, ASCII has no letters/figures code

42. - E9A03

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

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

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

44. - E9C01

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed 180 degrees out of phase?

Select	Answer
A	Omni-directional
B	A figure-8 broadside to the axis of the array
C	A figure-8 oriented along the axis of the array
D	Cardioid

45. - E9D01

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

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

46. - E9E09

Which of these matching systems is an effective method of connecting a 50 ohm coaxial cable feed line to a grounded tower so it can be used as a vertical antenna?

Select	Answer
A	All of these choices are correct
B	Gamma match
C	Double-bazooka match
D	Hairpin match

47. - E9F06

What is the approximate physical length of an air-insulated, parallel conductor transmission line that is electrically one-half wavelength long at 14.10 MHz?

Select	Answer
A	71 meters
B	20 meters
C	15 meters
D	10 meters

48. - E9G02

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

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

49. - E9H11

What characteristic of a cardioid pattern antenna is useful for direction finding?

Select	Answer
A	A very sharp peak
B	A very sharp single null
C	Broad band response
D	High-radiation angle

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