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

2. - E1B09

Which amateur stations may be operated under RACES rules?

Select	Answer
A	Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served
B	Any FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)
C	Any FCC-licensed amateur station except a Technician class
D	Only those club stations licensed to Amateur Extra class operators

3. - E1C07

What is meant by local control?

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

4. - E1D04

What is an Earth station in the amateur satellite service?

Select	Answer
A	An amateur station that is not able to communicate using amateur satellites
B	An amateur station that transmits telemetry consisting of measurement of upper atmosphere
C	An amateur station within 50 km of the Earth's surface intended for communications with amateur stations by means of objects in space
D	Any amateur station on the surface of the Earth

5. - E1E05

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

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

6. - E1F08

Which of the following types of amateur station communications are prohibited?

Select	Answer
A	Communications that have a political content, except as allowed by the Fairness Doctrine
B	Communications that have a religious content
C	Communications in a language other than English
D	Communications transmitted for hire or material compensation, except as otherwise provided in the rules

7. - E2A05

What do the letters in a satellite's mode designator specify?

Select	Answer
A	The location of the ground control station
B	Power limits for uplink and downlink transmissions
C	The uplink and downlink frequency ranges
D	The polarization of uplink and downlink signals

8. - E2B07

What is the name of the signal component that carries color information in NTSC video?

Select	Answer
A	Hue
B	Chroma
C	Luminance
D	Spectral Intensity

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. - E2D12

How does JT65 improve EME communications?

Select	Answer
A	It supplies signals to guide the antenna to track the Moon
B	It controls the receiver to track Doppler shift
C	It can decode signals many dB below the noise floor using FEC
D	All of these choices are correct

11. - E2E12

Which type of control is used by stations using the Automatic Link Enable (ALE) protocol?

Select	Answer
A	ALE can use any type of control
B	Automatic
C	Local
D	Remote

12. - E3A04

What do Hepburn maps predict?

Select	Answer
A	Probability of tropospheric propagation
B	Sporadic E propagation
C	Locations of auroral reflecting zones
D	Likelihood of rain-scatter along cold or warm fronts

13. - E3B10

What is the cause of gray-line propagation?

Select	Answer
A	At mid-afternoon, the Sun heats the ionosphere decreasing radio wave refraction and the MUF
B	In darkness, solar absorption drops greatly while atmospheric ionization remains steady
C	At midday, the Sun super heats the ionosphere causing increased refraction of radio waves
D	At twilight and sunrise, D-layer absorption is low while E-layer and F-layer propagation remains high

14. - E3C09

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

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

15. - E4A04

What determines the upper frequency limit for a computer soundcard-based oscilloscope program?

Select	Answer
A	All of these choices are correct
B	Q of the interface of the interface circuit
C	Amount of memory on the soundcard
D	Analog-to-digital conversion speed of the soundcard

16. - E4B10

Which of the following describes a method to measure intermodulation distortion in an SSB transmitter?

Select	Answer
A	Modulate the transmitter with two harmonically related audio frequencies and observe the RF output with a peak reading wattmeter
B	Modulate the transmitter with two harmonically related audio frequencies and observe the RF output with a logic analyzer
C	Modulate the transmitter with two non-harmonically related radio frequencies and observe the RF output with a spectrum analyzer
D	Modulate the transmitter with two non-harmonically related audio frequencies and observe the RF output with a spectrum analyzer

17. - E4C01

What is an effect of excessive phase noise in the local oscillator section of a receiver?

Select	Answer
A	It reduces receiver sensitivity
B	It can cause strong signals on nearby frequencies to interfere with reception of weak signals
C	It limits the receiver's ability to receive strong signals
D	It decreases receiver third-order intermodulation distortion dynamic range

18. - E4D02

Which of the following describes two problems caused by poor dynamic range in a communications receiver?

Select	Answer
A	Oscillator instability and severe audio distortion of all but the strongest received signals
B	Cross-modulation of the desired signal and insufficient audio power to operate the speaker
C	Cross-modulation of the desired signal and desensitization from strong adjacent signals
D	Oscillator instability requiring frequent retuning and loss of ability to recover the opposite sideband

19. - E4E06

What is a major cause of atmospheric static?

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

20. - E5A01

What can cause the voltage across reactances in series to be larger than the voltage applied to them?

Select	Answer
A	Capacitance
B	Resonance
C	Resistance
D	Conductance

21. - E5B08

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 100 ohms, R is 100 ohms, and XL is 75 ohms?

Select	Answer
A	14 degrees with the voltage lagging the current
B	76 degrees with the voltage leading the current
C	76 degrees with the voltage lagging the current
D	14 degrees with the voltage leading the current

22. - E5C06

What does the impedance 50-j25 represent?

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

23. - E5D14

What is reactive power?

Select	Answer
A	Wattless, nonproductive power
B	Power consumed in circuit Q
C	Power consumed in wire resistance in an inductor
D	Power lost because of capacitor leakage

24. - E6A17

What are the names of the three terminals of a field-effect transistor?

Select	Answer
A	Emitter, base 1, base 2
B	Gate 1, gate 2, drain
C	Emitter, base, collector
D	Gate, drain, source

25. - E6B03

What special type of diode is capable of both amplification and oscillation?

Select	Answer
A	Zener
B	Junction
C	Point contact
D	Tunnel

26. - E6C08

In Figure E6-5, what is the schematic symbol for a NAND gate?

Select	Answer
A	4
B	2
C	1
D	3

27. - E6D16

What is the common name for a capacitor connected across a transformer secondary that is used to absorb transient voltage spikes?

Select	Answer
A	Snubber capacitor
B	Feedback capacitor
C	Trimmer capacitor
D	Clipper capacitor

28. - E6E08

How is voltage from a power supply normally furnished to the most common type of monolithic microwave integrated circuit (MMIC)?

Select	Answer
A	Directly to the bias voltage (VCC IN) lead
B	Through a resistor and/or RF choke connected to the amplifier output lead
C	Through a capacitor and RF choke connected to the amplifier input lead
D	MMICs require no operating bias

29. - E6F04

What is the photovoltaic effect?

Select	Answer
A	The tendency of a battery to discharge when used outside
B	The conversion of electrical energy to mechanical energy
C	The conversion of voltage to current when exposed to light
D	The conversion of light to electrical energy

30. - E7A07

What logical operation does a NAND gate perform?

Select	Answer
A	It produces logic "0" at its output if some but not all inputs are logic "1"
B	It produces logic "0" at its output only when all inputs are logic "0"
C	It produces logic "1" at its output only when all inputs are logic "1"
D	It produces logic "0" at its output only when all inputs are logic "1"

31. - E7B02

What is a Class D amplifier?

Select	Answer
A	A type of amplifier that uses switching technology to achieve high efficiency
B	A frequency doubling amplifier
C	An amplifier that uses drift-mode FETs for high efficiency
D	A low power amplifier that uses a differential amplifier for improved linearity

32. - E7C13

What is one advantage of a Pi-matching network over an L-matching network consisting of a single inductor and a single capacitor?

Select	Answer
A	The Q of Pi-networks can be varied depending on the component values chosen
B	L-networks cannot perform impedance transformation
C	Pi-networks have fewer components
D	Pi-networks are designed for balanced input and output

33. - E7D14

What is one purpose of a "bleeder" resistor in a conventional unregulated power supply?

Select	Answer
A	To improve output voltage regulation
B	To balance the low-voltage filament windings
C	To boost the amount of output current
D	To cut down on waste heat generated by the power supply

34. - E7E11

Which type of detector is used for demodulating SSB signals?

Select	Answer
A	Phase detector
B	Phase comparator
C	Discriminator
D	Product detector

35. - E7F13

What is the function of taps in a digital signal processing filter?

Select	Answer
A	Select the point at which baseband signals are generated
B	Provide access for debugging software
C	Provide incremental signal delays for filter algorithms
D	To reduce excess signal pressure levels

36. - E7G11

What absolute voltage gain can be expected from the circuit in Figure E7-4 when R1 is 3300 ohms and RF is 47 kilohms?

Select	Answer
A	7
B	14
C	0.07
D	28

37. - E7H07

How can an oscillator's microphonic responses be reduced?

Select	Answer
A	Using the oscillator only for CW and digital signals
B	Use of NP0 capacitors
C	Mechanically isolating the oscillator circuitry from its enclosure
D	Eliminating noise on the oscillator's power supply

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. - E8B06

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz when the maximum modulation frequency is 3.5 kHz?

Select	Answer
A	0.214
B	0.47
C	47
D	2.14

40. - E8C05

What is the necessary bandwidth of a 13-WPM international Morse code transmission?

Select	Answer
A	Approximately 13 Hz
B	Approximately 52 Hz
C	Approximately 26 Hz
D	Approximately 104 Hz

41. - E8D08

What parameter might indicate that excessively high input levels are causing distortion in an AFSK signal?

Select	Answer
A	Baud rate
B	Signal to noise ratio
C	Repeat Request Rate (RRR)
D	Intermodulation Distortion (IMD)

42. - E9A10

Which of the following choices is a way to improve the efficiency of a ground-mounted quarter-wave vertical antenna?

Select	Answer
A	Isolate the coax shield from ground
B	Reduce the diameter of the radiating element
C	Install a good radial system
D	Shorten the radiating element

43. - E9B15

What is the front-to-back ratio of the radiation pattern shown in Figure E9-2?

Select	Answer
A	28 dB
B	24 dB
C	3 dB
D	15 dB

44. - E9C13

What is the main effect of placing a vertical antenna over an imperfect ground?

Select	Answer
A	It causes increased SWR
B	It changes the impedance angle of the matching network
C	It reduces low-angle radiation
D	It reduces losses in the radiating portion of the antenna

45. - E9D03

Where should a high Q loading coil be placed to minimize losses in a shortened vertical antenna?

Select	Answer
A	At a voltage node
B	Near the center of the vertical radiator
C	As low as possible on the vertical radiator
D	As close to the transmitter as possible

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 gamma match
C	The stub match
D	The delta match

47. - E9F03

Why is the physical length of a coaxial cable transmission line shorter than its electrical length?

Select	Answer
A	The surge impedance is higher in a parallel feed line
B	Skin effect is less pronounced in the coaxial cable
C	Electrical signals move more slowly in a coaxial cable than in air
D	The characteristic impedance is higher in a parallel feed line

48. - E9G02

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

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

49. - E9H05

What is the main drawback of a wire-loop antenna for direction finding?

Select	Answer
A	It is practical for use only on VHF bands
B	It is non-rotatable
C	It receives equally well in all directions
D	It has a bidirectional pattern

50. - E0A10

What toxic material may be present in some electronic components such as high voltage capacitors and transformers?

Select	Answer
A	Polymorphic silicon
B	Polyethylene
C	Polychlorinated Biphenyls
D	Polytetrafluroethylene

Figure E6-5

Figure E7-4

Figure E9-2