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

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1. - E1A03

With your transceiver displaying the carrier frequency of phone signals, you hear a station calling CQ on 14.349 MHz USB. Is it legal to return the call using upper sideband on the same frequency?

Select	Answer
A	Yes, because you were not the station calling CQ
B	Yes, because the displayed frequency is within the 20 meter band
C	No, the sideband will extend beyond the band edge
D	No, U.S. stations are not permitted to use phone emissions above 14.340 MHz

2. - E1B11

What is the permitted mean power of any spurious emission relative to the mean power of the fundamental emission from a station transmitter or external RF amplifier installed after January 1, 2003 and transmitting on a frequency below 30 MHZ?

Select	Answer
A	At least 43 dB below
B	At least 53 dB below
C	At least 73 dB below
D	At least 63 dB below

3. - E1C08

What is the maximum permissible duration of a remotely controlled station's transmissions if its control link malfunctions?

Select	Answer
A	3 minutes
B	5 minutes
C	10 minutes
D	30 seconds

4. - E1D02

What is the amateur satellite service?

Select	Answer
A	A radio communications service using amateur radio stations on satellites
B	A radio navigation service using satellites for the purpose of self training, intercommunication and technical studies carried out by amateurs
C	A radio communications service using stations on Earth satellites for public service broadcast
D	A spacecraft launching service for amateur-built satellites

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 77%
C	Minimum passing score of 70%
D	Minimum passing score of 80%

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 south of the U.S.-Canadian border
C	A line roughly parallel to and east of the U.S. Pacific coastline
D	A line roughly parallel to and west of the U.S. Atlantic coastline

7. - E2A03

What is the orbital period of an Earth satellite?

Select	Answer
A	The point of maximum height of a satellite's orbit
B	The point of minimum height of a satellite's orbit
C	The time it takes for a satellite to complete one revolution around the Earth
D	The time it takes for a satellite to travel from perigee to apogee

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	30 or 60
C	180 or 360
D	60 or 100

9. - E2C05

What is the function of a DX QSL Manager?

Select	Answer
A	To allocate frequencies for DXpeditions
B	To relay calls to and from a DX station
C	To run a net to allow many stations to contact a rare DX station
D	To handle the receiving and sending of confirmation cards for a DX station

10. - E2D14

What is one advantage of using JT65 coding?

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

11. - E2E08

Which of the following HF digital modes can be used to transfer binary files?

Select	Answer
A	RTTY
B	AMTOR
C	PACTOR
D	Hellschreiber

12. - E3A02

What characterizes libration fading of an EME signal?

Select	Answer
A	The returning echo is several Hertz lower in frequency than the transmitted signal
B	A slow change in the pitch of the CW signal
C	A gradual loss of signal as the Sun rises
D	A fluttery irregular fading

13. - E3B14

What happens to linearly polarized radio waves that split into ordinary and extraordinary waves in the ionosphere?

Select	Answer
A	They are bent toward the magnetic poles
B	Their polarization is randomly modified
C	They become phase-locked
D	They become elliptically polarized

14. - E3C02

What is indicated by a rising A or K index?

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

15. - E4A10

Which of the following displays multiple digital signal states simultaneously?

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

16. - E4B03

If a frequency counter with a specified accuracy of +/- 1.0 ppm reads 146,520,000 Hz, what is the most the actual frequency being measured could differ from the reading?

Select	Answer
A	1.4652 MHz
B	14.652 kHz
C	165.2 Hz
D	146.52 Hz

17. - E4C06

A CW receiver with the AGC off has an equivalent input noise power density of -174 dBm/Hz. What would be the level of an unmodulated carrier input to this receiver that would yield an audio output SNR of 0 dB in a 400 Hz noise bandwidth?

Select	Answer
A	-174 dBm
B	-155 dBm
C	-148 dBm
D	-164 dBm

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

19. - E4E13

What might be the cause of a loud roaring or buzzing AC line interference that comes and goes at intervals?

Select	Answer
A	A defective doorbell or doorbell transformer inside a nearby residence
B	All of these choices are correct
C	A malfunctioning illuminated advertising display
D	Arcing contacts in a thermostatically controlled device

20. - E5A17

What is the result of increasing the Q of an impedance-matching circuit?

Select	Answer
A	It has no effect on impedance matching
B	Matching bandwidth is decreased
C	Matching bandwidth is increased
D	Matching range is increased

21. - E5B02

What is the term for the time it takes for a charged capacitor in an RC circuit to discharge to 36.8% of its initial voltage?

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

22. - E5C15

Which point in Figure E5-2 best represents the impedance of a series circuit consisting of a 300 ohm resistor and an 18 microhenry inductor at 3.505 MHz?

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

23. - E5D12

How many watts are consumed in a circuit having a power factor of 0.2 if the input is 100-VAC at 4 amperes?

Select	Answer
A	50 watts
B	80 watts
C	2000 watts
D	400 watts

24. - E6A14

How does DC input impedance at the gate of a field-effect transistor compare with the DC input impedance of a bipolar transistor?

Select	Answer
A	They are both low impedance
B	An FET has low input impedance; a bipolar transistor has high input impedance
C	An FET has high input impedance; a bipolar transistor has low input impedance
D	They are both high impedance

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	Extremely high reverse breakdown voltage
C	Reverse bias controls its forward voltage drop
D	Ability to dissipate large amounts of power

26. - E6C04

What is the primary advantage of tri-state logic?

Select	Answer
A	High speed operation
B	More efficient arithmetic operations
C	Ability to connect many device outputs to a common bus
D	Low power consumption

27. - E6D15

What is current in the primary winding of a transformer called if no load is attached to the secondary?

Select	Answer
A	Magnetizing current
B	Stabilizing current
C	Excitation current
D	Direct current

28. - E6E07

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

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

29. - E6F06

Which of these materials is affected the most by photoconductivity?

Select	Answer
A	A liquid semiconductor
B	A heavy metal
C	An ordinary metal
D	A crystalline semiconductor

30. - E7A10

What is a truth table?

Select	Answer
A	A list of inputs and corresponding outputs for a digital device
B	A table of logic symbols that indicate the high logic states of an op-amp
C	A diagram showing logic states when the digital device output is true
D	A table of logic symbols that indicate the logic states of an op-amp

31. - E7B07

Which of the following is a likely result when a Class C amplifier is used to amplify a single-sideband phone signal?

Select	Answer
A	Increased overall intelligibility
B	Signal distortion and excessive bandwidth
C	Reduced intermodulation products
D	Signal inversion

32. - E7C04

How does an impedance-matching circuit transform a complex impedance to a resistive impedance?

Select	Answer
A	It introduces transconductance to cancel the reactive part of impedance
B	It introduces negative resistance to cancel the resistive part of impedance
C	It cancels the reactive part of the impedance and changes the resistive part to a desired value
D	Network resistances are substituted for load resistances and reactances are matched to the resistances

33. - E7D01

What is one characteristic of a linear electronic voltage regulator?

Select	Answer
A	The control element duty cycle is proportional to the line or load conditions
B	It eliminates the need for a pass transistor
C	The conduction of a control element is varied to maintain a constant output voltage
D	It has a ramp voltage as its output

34. - E7E09

What occurs when an excessive amount of signal energy reaches a mixer circuit?

Select	Answer
A	Spurious mixer products are generated
B	Automatic limiting occurs
C	A beat frequency is generated
D	Mixer blanking occurs

35. - E7F14

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

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

36. - E7G03

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

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

37. - E7H10

What information is contained in the lookup table of a direct digital frequency synthesizer?

Select	Answer
A	The synthesizer frequency limits and frequency values stored in the radio memories
B	The amplitude values that represent a sine-wave output
C	The phase relationship between a reference oscillator and the output waveform
D	The phase relationship between a voltage-controlled oscillator and the output waveform

38. - E8A12

What is an advantage of using digital signals instead of analog signals to convey the same information?

Select	Answer
A	All of these choices are correct
B	Digital signals can be regenerated multiple times without error
C	Digital signals always occupy a narrower bandwidth
D	Less complex circuitry is required for digital signal generation and detection

39. - E8B05

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus-or-minus 5 kHz when the maximum modulation frequency is 3 kHz?

Select	Answer
A	60
B	0.6
C	1.67
D	0.167

40. - E8C04

What technique is used to minimize the bandwidth requirements of a PSK31 signal?

Select	Answer
A	Use of trapezoidal data pulses
B	Reed-Solomon character encoding
C	Zero-sum character encoding
D	Use of sinusoidal data pulses

41. - E8D01

Why are received spread spectrum signals resistant to interference?

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

42. - E9A09

How is antenna efficiency calculated?

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

43. - E9B06

What is the elevation angle of peak response in the antenna radiation pattern shown in Figure E9-2?

Select	Answer
A	75 degrees
B	25 degrees
C	7.5 degrees
D	45 degrees

44. - E9C02

What is the radiation pattern of two 1/4 wavelength vertical antennas spaced 1/4 wavelength apart and fed 90 degrees out of phase?

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

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

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

47. - E9F08

What is the term for the ratio of the actual speed at which a signal travels through a transmission line to the speed of light in a vacuum?

Select	Answer
A	Standing wave ratio
B	Surge impedance
C	Characteristic impedance
D	Velocity factor

48. - E9G05

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

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

49. - E9H04

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

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

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

Figure E5-2

Figure E9-2

Figure E9-3