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

2. - E1B10

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

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

3. - E1C10

What types of amateur stations may automatically retransmit the radio signals of other amateur stations?

Select	Answer
A	Only auxiliary, beacon or space stations
B	Only auxiliary, repeater or space stations
C	Only earth stations, repeater stations or model craft
D	Only beacon, repeater or space stations

4. - E1D01

What is the definition of the term telemetry?

Select	Answer
A	Two-way radiotelephone transmissions in excess of 1000 feet
B	One-way transmission of measurements at a distance from the measuring instrument
C	Two-way single channel transmissions of data
D	One-way transmission that initiates, modifies, or terminates the functions of a device at a distance

5. - E1E05

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

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

6. - E1F01

On what frequencies are spread spectrum transmissions permitted?

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

7. - E2A02

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

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

8. - E2B13

How many lines are commonly used in each frame of an amateur slow-scan color television picture?

Select	Answer
A	128 or 256
B	60 or 100
C	180 or 360
D	30 or 60

9. - E2C09

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

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

10. - E2D09

Which of these digital modes has the fastest data throughput under clear communication conditions?

Select	Answer
A	PSK31
B	170 Hz shift, 45 baud RTTY
C	AMTOR
D	300 baud packet

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	Pulse modulation
D	FSK

12. - E3A03

When scheduling EME contacts, which of these conditions will generally result in the least path loss?

Select	Answer
A	When the Moon is full
B	When the Moon is at perigee
C	When the MUF is above 30 MHz
D	When the Moon is at apogee

13. - E3B08

What type of HF propagation is probably occurring if radio signals travel along the terminator between daylight and darkness?

Select	Answer
A	Long-path
B	Gray-line
C	Sporadic-E
D	Transequatorial

14. - E3C09

How does the intensity of an X3 flare compare to that of an X2 flare?

Select	Answer
A	Twice as great
B	50 percent greater
C	Four times as great
D	10 percent greater

15. - E4A10

Which of the following displays multiple digital signal states simultaneously?

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

16. - E4B09

What is indicated if the current reading on an RF ammeter placed in series with the antenna feed line of a transmitter increases as the transmitter is tuned to resonance?

Select	Answer
A	There is more power going into the antenna
B	The transmitter is not properly neutralized
C	There is an impedance mismatch between the antenna and feed line
D	There is possibly a short to ground in the feed line

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	14.445 MHz
B	13.845 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 band-pass filter in the feed line between the transmitter and receiver
B	A properly terminated circulator at the output of the transmitter
C	A Class D final amplifier
D	A Class C final amplifier

19. - E4E01

Which of the following types of receiver noise can often be reduced by use of a receiver noise blanker?

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

20. - E5A13

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

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

21. - E5B05

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

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

22. - E5C04

Which of the following represents a capacitive reactance in polar coordinates?

Select	Answer
A	A negative phase angle
B	A positive phase angle
C	A positive real part
D	A negative real part

23. - E5D05

Which parasitic characteristic increases with conductor length?

Select	Answer
A	Malleability
B	Permittivity
C	Permeability
D	Inductance

24. - E6A06

What is the beta of a bipolar junction transistor?

Select	Answer
A	The change in collector current with respect to base current
B	The frequency at which the current gain is reduced to 1
C	The breakdown voltage of the base to collector junction
D	The switching speed of the transistor

25. - E6B02

What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

Select	Answer
A	Controlled reverse avalanche voltage
B	Much higher reverse voltage breakdown
C	Less forward voltage drop
D	Enhanced carrier retention time

26. - E6C09

What is a Programmable Logic Device (PLD)?

Select	Answer
A	Programmable equipment used for testing digital logic integrated circuits
B	A programmable collection of logic gates and circuits in a single integrated circuit
C	A device to control industrial equipment
D	An algorithm for simulating logic functions during circuit design

27. - E6D13

What is the primary cause of inductor self-resonance?

Select	Answer
A	The skin effect
B	Inter-turn capacitance
C	Inductive kickback
D	Non-linear core hysteresis

28. - E6E01

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

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

29. - E6F14

Which of the following is true of LCD displays?

Select	Answer
A	All of these choices are correct
B	They only display alphanumeric symbols
C	They may be hard view through polarized lenses
D	They are hard to view in high ambient light conditions

30. - E7A04

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

Select	Answer
A	1
B	2
C	4
D	8

31. - E7B14

Why are switching amplifiers more efficient than linear amplifiers?

Select	Answer
A	Switching amplifiers use push-pull circuits
B	Linear amplifiers have high gain resulting in higher harmonic content
C	The power transistor is at saturation or cut off most of the time, resulting in low power dissipation
D	Switching amplifiers operate at higher voltages

32. - E7C12

Which describes a Pi-L-network used for matching a vacuum tube final amplifier to a 50 ohm unbalanced output?

Select	Answer
A	A network with only three discrete parts
B	A Phase Inverter Load network
C	A Pi-network with an additional series inductor on the output
D	A matching network in which all components are isolated from ground

33. - E7D15

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

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

34. - E7E01

Which of the following can be used to generate FM phone emissions?

Select	Answer
A	A reactance modulator on the oscillator
B	A balanced modulator on the oscillator
C	A reactance modulator on the final amplifier
D	A balanced modulator on the audio amplifier

35. - E7F14

Which of the following would allow a digital signal processing filter to create a sharper filter response?

Select	Answer
A	Double-precision math routines
B	Higher data rate
C	Complex phasor representations
D	More taps

36. - E7G01

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

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

37. - E7H11

What are the major spectral impurity components of direct digital synthesizers?

Select	Answer
A	Broadband noise
B	Nyquist limit noise
C	Spurious signals at discrete frequencies
D	Digital conversion noise

38. - E8A07

What determines the PEP-to-average power ratio of a single-sideband phone signal?

Select	Answer
A	The amplifier gain
B	The degree of carrier suppression
C	The characteristics of the modulating signal
D	The frequency of the modulating signal

39. - E8B11

What is digital time division multiplexing?

Select	Answer
A	Two or more signals are arranged to share discrete time slots of a data transmission
B	Two or more signals are quadrature modulated to increase bandwidth efficiency
C	Two or more data streams are assigned to discrete sub-carriers on an FM transmitter
D	Two or more data streams share the same channel by transmitting time of transmission as the sub-carrier

40. - E8C11

What is the relationship between symbol rate and baud?

Select	Answer
A	Symbol rate is only used for packet-based modes
B	Baud is only used for RTTY
C	Baud is twice the symbol rate
D	They are the same

41. - E8D06

Which of the following indicates likely overmodulation of an AFSK signal such as PSK or MFSK?

Select	Answer
A	Rapid signal fading
B	High reflected power
C	Strong ALC action
D	Harmonics on higher bands

42. - E9A18

What term describes station output, taking into account all gains and losses?

Select	Answer
A	Half-power bandwidth
B	Power factor
C	Effective radiated power
D	Apparent power

43. - E9B09

What type of computer program technique is commonly used for modeling antennas?

Select	Answer
A	Mutual impedance analysis
B	Method of Moments
C	Calculus differentiation with respect to physical properties
D	Graphical analysis

44. - E9C05

What is an OCFD antenna?

Select	Answer
A	A dipole feed approximately 1/3 the way from one end with a 4:1 balun to provide multiband operation
B	An eight band dipole antenna using octophase filters
C	A multiband dipole antenna using one-way circular polarization for frequency diversity
D	A remotely tunable dipole antenna using orthogonally controlled frequency diversity

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. - 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 gamma match
B	The stub match
C	The delta match
D	The epsilon match

47. - E9F13

What impedance does a 1/4 wavelength transmission line present to a generator when the line is shorted at the far end?

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

48. - E9G05

What type of chart is shown in Figure E9-3?

Select	Answer
A	Azimuth angle radiation pattern chart
B	Elevation angle radiation pattern chart
C	Free space radiation directivity chart
D	Smith chart

49. - E9H11

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

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

50. - E0A07

How may dangerous levels of carbon monoxide from an emergency generator be detected?

Select	Answer
A	By the odor
B	Only with a carbon monoxide detector
C	By the yellowish appearance of the gas
D	Any ordinary smoke detector can be used

Figure E9-3