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

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1. - E1A14

What is the maximum bandwidth for a data emission on 60 meters?

Select	Answer
A	1.5 kHz
B	170 Hz
C	2.8 kHz
D	60 Hz

2. - E1B07

What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?

Select	Answer
A	1.0
B	2.0
C	3.0
D	0.5

3. - E1C11

Which of the following operating arrangements allows an FCC-licensed U.S. citizen to operate in many European countries, and alien amateurs from many European countries to operate in the U.S.?

Select	Answer
A	IARP agreement
B	ITU reciprocal license
C	CEPT agreement
D	All of these choices are correct

4. - E1D07

Which amateur service HF bands have frequencies authorized for space stations?

Select	Answer
A	All HF bands
B	Only the 40 m, 20 m, 17 m, 15 m and 10 m bands
C	Only the 40 m, 30 m, 20 m, 15 m, 12 m and 10 m bands
D	Only the 40 m, 20 m, 17 m, 15 m, 12 m and 10 m bands

5. - E1E02

Where are the questions for all written U.S. amateur license examinations listed?

Select	Answer
A	In FCC Part 97
B	In the appropriate FCC Report and Order
C	In a question pool maintained by the FCC
D	In a question pool maintained by all the VECs

6. - E1F04

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

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

7. - E2A01

What is the direction of an ascending pass for an amateur satellite?

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

8. - E2B01

How many times per second is a new frame transmitted in a fast-scan (NTSC) television system?

Select	Answer
A	90
B	120
C	30
D	60

9. - E2C06

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

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

10. - E2D08

What type of packet frame is used to transmit APRS beacon data?

Select	Answer
A	Acknowledgement
B	Unnumbered Information
C	Disconnect
D	Connect

11. - E2E03

How is the timing of JT65 contacts organized?

Select	Answer
A	By exchanging ACK/NAK packets
B	Alternating transmissions at 1 minute intervals
C	It depends on the lunar phase
D	Stations take turns on alternate days

12. - E3A17

What is meant by circularly polarized electromagnetic waves?

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

13. - E3B09

At what time of year is Sporadic E propagation most likely to occur?

Select	Answer
A	Around the solstices, especially the summer solstice
B	Around the equinoxes, especially the fall equinox
C	Around the solstices, especially the winter solstice
D	Around the equinoxes, especially the spring equinox

14. - E3C15

What might a sudden rise in radio background noise indicate?

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

15. - E4A08

Which of the following instrument would be best for measuring the SWR of a beam antenna?

Select	Answer
A	A Q meter
B	An ohmmeter
C	A spectrum analyzer
D	An antenna analyzer

16. - E4B02

What is an advantage of using a bridge circuit to measure impedance?

Select	Answer
A	It provides an excellent match under all conditions
B	It can display results directly in Smith chart format
C	It is relatively immune to drift in the signal generator source
D	It is very precise in obtaining a signal null

17. - E4C05

What does a value of -174 dBm/Hz represent with regard to the noise floor of a receiver?

Select	Answer
A	The minimum detectable signal as a function of receive frequency
B	The theoretical noise at the input of a perfect receiver at room temperature
C	The galactic noise contribution to minimum detectable signal
D	The noise figure of a 1 Hz bandwidth receiver

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

19. - E4E03

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

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

20. - E5A13

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

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

21. - E5B13

What letter is commonly used to represent susceptance?

Select	Answer
A	X
B	G
C	B
D	Y

22. - E5C06

What does the impedance 50-j25 represent?

Select	Answer
A	25 ohms resistance in series with 50 ohms capacitive reactance
B	25 ohms resistance in series with 50 ohms inductive reactance
C	50 ohms resistance in series with 25 ohms capacitive reactance
D	50 ohms resistance in series with 25 ohms inductive reactance

23. - E5D13

How much power is consumed in a circuit consisting of a 100 ohm resistor in series with a 100 ohm inductive reactance drawing 1 ampere?

Select	Answer
A	100 Watts
B	70.7 Watts
C	141.4 Watts
D	200 Watts

24. - E6A01

In what application is gallium arsenide used as a semiconductor material in preference to germanium or silicon?

Select	Answer
A	In high-power audio circuits
B	In microwave circuits
C	In very low frequency RF circuits
D	In high-current rectifier circuits

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

26. - E6C07

What best describes a pull-up or pull-down resistor?

Select	Answer
A	A resistor connected to the positive or negative supply line used to establish a voltage when an input or output is an open circuit
B	A resistor that insures that an oscillator frequency does not drive lower over time
C	A resistor in a keying circuit used to reduce key clicks
D	A resistor connected to an op-amp output that only functions when the logic output is false

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

28. - E6E07

Which of the following is typically used to construct a MMIC-based microwave amplifier?

Select	Answer
A	Ground-plane construction
B	Microstrip construction
C	Point-to-point construction
D	Wave-soldering construction

29. - E6F08

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

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

30. - E7A12

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

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

31. - E7B13

In Figure E7-2, what is the purpose of R?

Select	Answer
A	Collector load
B	Fixed bias
C	Voltage regulation
D	Emitter load

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 Pi-network with an additional series inductor on the output
B	A network with only three discrete parts
C	A Phase Inverter Load network
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 compensate for variations of the incoming line voltage
B	To allow for remote control of the power supply
C	To provide a dual-voltage output for reduced power applications
D	To allow the filter capacitors to charge gradually

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

35. - E7F07

What function can a Fast Fourier Transform perform?

Select	Answer
A	Converting digital signals to analog form
B	Converting analog signals to digital form
C	Converting 8-bit data to 16 bit data
D	Converting digital signals from the time domain to the frequency domain

36. - E7G06

Which of the following is the most appropriate use of an op-amp active filter?

Select	Answer
A	As a high-pass filter used to block RFI at the input to receivers
B	As an audio filter in a receiver
C	For smoothing power supply output
D	As a low-pass filter used between a transmitter and a transmission line

37. - E7H06

Which of the following oscillator circuits are commonly used in VFOs?

Select	Answer
A	Colpitts and Hartley
B	Pierce and Zener
C	Armstrong and deForest
D	Negative feedback and balanced feedback

38. - E8A02

What type of wave has a rise time significantly faster than its fall time (or vice versa)?

Select	Answer
A	A sawtooth wave
B	A square wave
C	A sine wave
D	A cosine wave

39. - E8B09

What is meant by deviation ratio?

Select	Answer
A	The ratio of the carrier center frequency to the audio modulating frequency
B	The ratio of the audio modulating frequency to the center carrier frequency
C	The ratio of the highest audio modulating frequency to the average audio modulating frequency
D	The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency

40. - E8C02

What is the definition of symbol rate in a digital transmission?

Select	Answer
A	The duration of each bit in a message sent over the air
B	The rate at which the waveform of a transmitted signal changes to convey information
C	The number of characters carried per second by the station-to-station link
D	The number of control characters in a message packet

41. - E8D05

What is the most common method of reducing key clicks?

Select	Answer
A	High-pass filters at the transmitter output
B	Reduce keying waveform rise and fall times
C	Increase keying waveform rise and fall times
D	Low-pass filters at the transmitter output

42. - E9A09

How is antenna efficiency calculated?

Select	Answer
A	(total resistance / radiation resistance) x 100 per cent
B	(radiation resistance / total resistance) x 100 per cent
C	(radiation resistance / transmission resistance) x 100 per cent
D	(effective radiated power / transmitter output) x 100 percent

43. - E9B03

In the antenna radiation pattern shown in Figure E9-1, what is the front-to-side ratio?

Select	Answer
A	12 dB
B	18 dB
C	14 dB
D	24 dB

44. - E9C15

How does the radiation pattern of a horizontally polarized 3-element beam antenna vary with its height above ground?

Select	Answer
A	The main lobe takeoff angle decreases with increasing height
B	The main lobe takeoff angle increases with increasing height
C	The horizontal beam width decreases with height
D	The horizontal beam width increases with height

45. - E9D12

Which of the following would provide the best RF ground for your station?

Select	Answer
A	An electrically short connection to 3 or 4 interconnected ground rods via a series RF choke
B	An electrically short connection to 3 or 4 interconnected ground rods driven into the Earth
C	A 50 ohm resistor connected to ground
D	An electrically short connection to a metal water pipe

46. - E9E07

What term best describes the interactions at the load end of a mismatched transmission line?

Select	Answer
A	Velocity factor
B	Characteristic impedance
C	Dielectric constant
D	Reflection coefficient

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	10 meters
B	20 meters
C	71 meters
D	15 meters

48. - E9G02

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

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

49. - E9H09

Which of the following describes the construction of a receiving loop antenna?

Select	Answer
A	A small coil of wire tightly wound around a toroidal ferrite core
B	A large circularly polarized antenna
C	One or more turns of wire wound in the shape of a large open coil
D	A vertical antenna coupled to a feed line through an inductive loop of wire

50. - E0A03

Which of the following would be a practical way to estimate whether the RF fields produced by an amateur radio station are within permissible MPE limits?

Select	Answer
A	Use an antenna modeling program to calculate field strength at accessible locations
B	Use a calibrated antenna analyzer
C	All of the choices are correct
D	Use a hand calculator plus Smith-chart equations to calculate the fields

Figure E7-2

Figure E9-1