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

2. - E1B02

Which of the following factors might cause the physical location of an amateur station apparatus or antenna structure to be restricted?

Select	Answer
A	The location is in an ITU Zone designated for coordination with one or more foreign governments
B	The location is near an area of political conflict
C	The location is of environmental importance or significant in American history, architecture, or culture
D	The location is of geographical or horticultural importance

3. - E1C07

What is meant by local control?

Select	Answer
A	Automatically manipulating local station controls
B	Direct manipulation of the transmitter by a control operator
C	Controlling a repeater using a portable handheld transceiver
D	Controlling a station through a local auxiliary link

4. - E1D09

Which UHF amateur service bands have frequencies available for a space station?

Select	Answer
A	70 cm and 33 cm
B	70 cm and 13 cm
C	70 cm only
D	33 cm and 13 cm

5. - E1E09

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

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

6. - E1F04

Which of the following geographic descriptions approximately describes "Line A"?

Select	Answer
A	A line roughly parallel to and west of the U.S. Atlantic coastline
B	A line roughly parallel to and north of the U.S.-Mexican border and Gulf coastline
C	A line roughly parallel to and east of the U.S. Pacific coastline
D	A line roughly parallel to and south of the U.S.-Canadian border

7. - E2A12

What is one way to predict the location of a satellite at a given time?

Select	Answer
A	By subtracting the mean anomaly from the orbital inclination
B	By means of the Doppler data for the specified satellite
C	By adding the mean anomaly to the orbital inclination
D	By calculations using the Keplerian elements for the specified satellite

8. - E2B12

How are analog SSTV images typically transmitted on the HF bands?

Select	Answer
A	Varying tone frequencies representing the video are transmitted using single sideband
B	Varying tone frequencies representing the video are transmitted using PSK
C	Video is converted to equivalent Baudot representation
D	Video is converted to equivalent ASCII representation

9. - E2C09

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

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

10. - E2D06

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

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

11. - E2E01

Which type of modulation is common for data emissions below 30 MHz?

Select	Answer
A	DTMF tones modulating an FM signal
B	Spread spectrum
C	FSK
D	Pulse modulation

12. - E3A17

What is meant by circularly polarized electromagnetic waves?

Select	Answer
A	Waves with an electric field bent into a circular shape
B	Waves produced by a loop antenna
C	Waves with a rotating electric field
D	Waves that circle the Earth

13. - E3B07

Which of the following could account for hearing an echo on the received signal of a distant station?

Select	Answer
A	Meteor scatter
B	Receipt of a signal by more than one path
C	High D layer absorption
D	Transmit frequency is higher than the MUF

14. - E3C06

By how much does the VHF/UHF radio horizon distance exceed the geometric horizon?

Select	Answer
A	By approximately 50 percent of the distance
B	By approximately four times the distance
C	By approximately twice the distance
D	By approximately 15 percent of the distance

15. - E4A06

What is the effect of aliasing in a digital or computer-based oscilloscope?

Select	Answer
A	All signals will have a DC offset
B	False triggering occurs
C	False signals are displayed
D	Calibration of the vertical scale is no longer valid

16. - E4B13

Which S parameter is equivalent to forward gain?

Select	Answer
A	S22
B	S11
C	S21
D	S12

17. - E4C12

What is an undesirable effect of using too wide a filter bandwidth in the IF section of a receiver?

Select	Answer
A	Undesired signals may be heard
B	Thermal-noise distortion
C	Output-offset overshoot
D	Filter ringing

18. - E4D01

What is meant by the blocking dynamic range of a receiver?

Select	Answer
A	The minimum difference in dB between two signals which produce third order intermodulation products greater than the noise floor
B	The difference in dB between the noise floor and the level of an incoming signal which will cause 1 dB of gain compression
C	The difference in dB between the noise floor and the third order intercept point
D	The minimum difference in dB between the levels of two FM signals which will cause one signal to block the other

19. - E4E03

Which of the following signals might a receiver noise blanker be able to remove from desired signals?

Select	Answer
A	Signals which have a sharply peaked frequency distribution
B	Signals which are constant at all IF levels
C	Signals which appear across a wide bandwidth
D	Signals which appear at one IF but not another

20. - E5A13

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

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

21. - E5B01

What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the applied voltage?

Select	Answer
A	A time factor of one
B	One time constant
C	An exponential rate of one
D	One exponential period

22. - E5C16

Which point on Figure E5-2 best represents the impedance of a series circuit consisting of a 300 ohm resistor and a 19 picofarad capacitor at 21.200 MHz?

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

23. - E5D03

What is microstrip?

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

24. - E6A12

Why do many MOSFET devices have internally connected Zener diodes on the gates?

Select	Answer
A	To protect the substrate from excessive voltages
B	To reduce the chance of the gate insulation being punctured by static discharges or excessive voltages
C	To keep the gate voltage within specifications and prevent the device from overheating
D	To provide a voltage reference for the correct amount of reverse-bias gate voltage

25. - E6B05

What characteristic of a PIN diode makes it useful as an RF switch or attenuator?

Select	Answer
A	A large region of intrinsic material
B	Ability to dissipate large amounts of power
C	Reverse bias controls its forward voltage drop
D	Extremely high reverse breakdown voltage

26. - E6C05

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

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

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

28. - E6E05

Which of the following noise figure values is typical of a low-noise UHF preamplifier?

Select	Answer
A	-10 dB
B	2 dB
C	-20 dBm
D	44 dBm

29. - E6F08

Why are optoisolators often used in conjunction with solid state circuits when switching 120VAC?

Select	Answer
A	Optoisolators provide impedance matching between the control circuit and power circuit
B	Optoisolators eliminate the effects of reflected light in the control circuit
C	Optoisolators provide a low impedance link between a control circuit and a power circuit
D	Optoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched

30. - E7A01

Which is a bi-stable circuit?

Select	Answer
A	A clock
B	A flip-flop
C	An "AND" gate
D	An "OR" gate

31. - E7B10

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

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

32. - E7C07

What kind of filter would you use to attenuate an interfering carrier signal while receiving an SSB transmission?

Select	Answer
A	A Pi-network filter
B	An all-pass filter
C	A band-pass filter
D	A notch filter

33. - E7D15

What is the purpose of a "step-start" circuit in a high voltage power supply?

Select	Answer
A	To compensate for variations of the incoming line voltage
B	To allow for remote control of the power supply
C	To allow the filter capacitors to charge gradually
D	To provide a dual-voltage output for reduced power applications

34. - E7E03

How does an analog phase modulator function?

Select	Answer
A	By varying the tuning of an amplifier tank circuit to produce AM signals
B	By varying the tuning of a microphone preamplifier to produce PM signals
C	By varying the tuning of a microphone preamplifier to produce AM signals
D	By varying the tuning of an amplifier tank circuit to produce PM signals

35. - E7F17

What do the letters I and Q in I/Q Modulation represent?

Select	Answer
A	Instantaneous and Quasi-stable
B	Instantaneous and Quenched
C	Inactive and Quiescent
D	In-phase and Quadrature

36. - E7G05

How can unwanted ringing and audio instability be prevented in a multi-section op-amp RC audio filter circuit?

Select	Answer
A	Restrict gain but increase Q
B	Restrict Q but increase gain
C	Restrict both gain and Q
D	Increase both gain and Q

37. - E7H05

How is positive feedback supplied in a Pierce oscillator?

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

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 using an absorption wave meter
D	By measuring the heating effect in a known resistor

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	Modulation index
C	Percentage of modulation
D	FM compressibility

40. - E8C08

How does ARQ accomplish error correction?

Select	Answer
A	Special binary codes provide automatic correction
B	Special polynomial codes provide automatic correction
C	If errors are detected, a retransmission is requested
D	If errors are detected, redundant data is substituted

41. - E8D07

What is a common cause of overmodulation of AFSK signals?

Select	Answer
A	Excessive numbers of retries
B	Excessive transmit audio levels
C	Bit errors in the modem
D	Ground loops

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 match impedances in order to minimize standing wave ratio on the transmission line
C	To calculate the front-to-side ratio of the antenna
D	To calculate the front-to-back ratio of the antenna

43. - E9B10

What is the principle of a Method of Moments analysis?

Select	Answer
A	A wire is modeled as a series of segments, each having a distinct value of voltage across it
B	A wire is modeled as a series of points, each having a distinct location in space
C	A wire is modeled as a series of segments, each having a uniform value of current
D	A wire is modeled as a single sine-wave current generator

44. - E9C03

What is the radiation pattern of two 1/4 wavelength vertical antennas spaced a 1/2 wavelength apart and fed in phase?

Select	Answer
A	Omni-directional
B	A Figure-8 broadside to the axis of the array
C	Cardioid
D	A Figure-8 end-fire along the axis of the array

45. - E9D02

How can linearly polarized Yagi antennas be used to produce circular polarization?

Select	Answer
A	Stack two Yagis fed 90 degrees out of phase to form an array with the respective elements in parallel planes
B	Arrange two Yagis perpendicular to each other with the driven elements at the same point on the boom fed 90 degrees out of phase
C	Stack two Yagis fed in phase to form an array with the respective elements in parallel planes
D	Arrange two Yagis collinear to each other with the driven elements fed 180 degrees out of phase

46. - E9E02

What is the name of an antenna matching system that matches an unbalanced feed line to an antenna by feeding the driven element both at the center of the element and at a fraction of a wavelength to one side of center?

Select	Answer
A	The epsilon match
B	The stub match
C	The delta match
D	The gamma match

47. - E9F10

What impedance does a 1/8 wavelength transmission line present to a generator when the line is shorted at the far end?

Select	Answer
A	The same as the input impedance to the final generator stage
B	An inductive reactance
C	The same as the characteristic impedance of the line
D	A capacitive reactance

48. - E9G02

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

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

49. - E9H04

What is an advantage of using a shielded loop antenna for direction finding?

Select	Answer
A	It eliminates tracking errors caused by strong out-of-band signals
B	It automatically cancels ignition noise in mobile installations
C	It is electro statically balanced against ground, giving better nulls
D	It allows stations to communicate without giving away their position

50. - E0A11

Which of the following injuries can result from using high-power UHF or microwave transmitters?

Select	Answer
A	Blood clotting from the intense magnetic field
B	Localized heating of the body from RF exposure in excess of the MPE limits
C	Ingestion of ozone gas from the cooling system
D	Hearing loss caused by high voltage corona discharge

Figure E5-2

Figure E7-1