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

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1. - E1A12

With your transceiver displaying the carrier frequency of CW signals, you hear a DX station's CQ on 3.500 MHz. Is it legal to return the call using CW on the same frequency?

Select	Answer
A	No, one of the sidebands of the CW signal will be out of the band
B	Yes, the displayed frequency is within the 80 meter CW band segment
C	Yes, the DX station initiated the contact
D	No, U.S. stations are not permitted to use CW emissions below 3.525 MHz

2. - E1B06

Which of the following additional rules apply if you are installing an amateur station antenna at a site at or near a public use airport?

Select	Answer
A	You may have to notify the Federal Aviation Administration and register it with the FCC as required by Part 17 of FCC rules
B	No special rules apply if your antenna structure will be less than 300 feet in height
C	You must obtain a construction permit from the airport zoning authority
D	You must file an Environmental Impact Statement with the EPA before construction begins

3. - E1C12

What types of communications may be transmitted to amateur stations in foreign countries?

Select	Answer
A	Messages intended for connection to users of the maritime satellite service
B	Communications incidental to the purpose of the amateur service and remarks of a personal nature
C	All of these choices are correct
D	Business-related messages for non-profit organizations

4. - E1D04

What is an Earth station in the amateur satellite service?

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

5. - E1E13

Which of these choices is an acceptable method for monitoring the applicants if a VEC opts to conduct an exam session remotely?

Select	Answer
A	Use a real-time video link and the Internet to connect the exam session to the observing VEs
B	Have each applicant sign an affidavit stating that all session rules were followed
C	Record the exam session on video tape for later review by the VE team
D	The exam proctor observes the applicants and reports any violations

6. - E1F01

On what frequencies are spread spectrum transmissions permitted?

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

7. - E2A14

What technology is used to track, in real time, balloons carrying amateur radio transmitters?

Select	Answer
A	APRS
B	Radar
C	Doppler shift of beacon signals
D	Bandwidth compressed LORAN

8. - E2B02

How many horizontal lines make up a fast-scan (NTSC) television frame?

Select	Answer
A	525
B	60
C	30
D	1080

9. - E2C07

What is the Cabrillo format?

Select	Answer
A	The most common set of contest rules
B	The rules of order for meetings between contest sponsors
C	A standard for submission of electronic contest logs
D	A method of exchanging information during a contest QSO

10. - E2D08

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

Select	Answer
A	Acknowledgement
B	Unnumbered Information
C	Connect
D	Disconnect

11. - E2E01

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

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

12. - E3A14

From the contiguous 48 states, in which approximate direction should an antenna be pointed to take maximum advantage of aurora propagation?

Select	Answer
A	South
B	North
C	West
D	East

13. - E3B05

Which amateur bands typically support long-path propagation?

Select	Answer
A	6 meters to 2 meters
B	30 meters to 10 meters
C	160 meters to 40 meters
D	160 meters to 10 meters

14. - E3C03

Which of the following signal paths is most likely to experience high levels of absorption when the A index or K index is elevated?

Select	Answer
A	NVIS
B	Transequatorial propagation
C	Sporadic-E
D	Polar paths

15. - E4A13

How is the compensation of an oscilloscope probe typically adjusted?

Select	Answer
A	A frequency standard is displayed and the probe is adjusted until the deflection time is accurate
B	A DC voltage standard is displayed and the probe is adjusted until the displayed voltage is accurate
C	A square wave is displayed and the probe is adjusted until the horizontal portions of the displayed wave are as nearly flat as possible
D	A high frequency sine wave is displayed and the probe is adjusted for maximum amplitude

16. - E4B15

Which of the following can be used as a relative measurement of the Q for a series-tuned circuit?

Select	Answer
A	The frequency shift
B	The resonant frequency of the circuit
C	The inductance to capacitance ratio
D	The bandwidth of the circuit's frequency response

17. - E4C07

What does the MDS of a receiver represent?

Select	Answer
A	The minimum discernible signal
B	The maximum detectable spectrum
C	The meter display sensitivity
D	The multiplex distortion stability

18. - E4D10

What does a third-order intercept level of 40 dBm mean with respect to receiver performance?

Select	Answer
A	A pair of 40 dBm signals will theoretically generate a third-order intermodulation product with the same level as the input signals
B	The receiver can tolerate signals up to 40 dB above the noise floor without producing third-order intermodulation products
C	A pair of 1 mW input signals will produce a third-order intermodulation product which is 40 dB stronger than the input signal
D	Signals less than 40 dBm will not generate audible third-order intermodulation products

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	A malfunctioning illuminated advertising display
C	All of these choices are correct
D	Arcing contacts in a thermostatically controlled device

20. - E5A11

What is the half-power bandwidth of a parallel resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150?

Select	Answer
A	315.6 Hz
B	157.8 Hz
C	23.67 kHz
D	47.3 kHz

21. - E5B12

What is admittance?

Select	Answer
A	The turns ratio of a transformer
B	The inverse of impedance
C	The term for the gain of a field effect transistor
D	The unit used for Q factor

22. - E5C10

When using rectangular coordinates to graph the impedance of a circuit, what does the vertical axis represent?

Select	Answer
A	Resistive component
B	The sum of the reactive and resistive components
C	Reactive component
D	The difference between the resistive and reactive components

23. - E5D10

How can the true power be determined in an AC circuit where the voltage and current are out of phase?

Select	Answer
A	By multiplying the apparent power times the power factor
B	By multiplying the reactive power times the power factor
C	By dividing the reactive power by the power factor
D	By dividing the apparent power by the power factor

24. - E6A02

Which of the following semiconductor materials contains excess free electrons?

Select	Answer
A	P-type
B	N-type
C	Bipolar
D	Insulated gate

25. - E6B09

What is a common use for point contact diodes?

Select	Answer
A	As a constant voltage source
B	As a constant current source
C	As a high voltage rectifier
D	As an RF detector

26. - E6C07

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

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

27. - E6D11

How many turns will be required to produce a 1-mH inductor using a core that has an inductance index (A L) value of 523 millihenrys/1000 turns?

Select	Answer
A	4 turns
B	2 turns
C	229 turns
D	43 turns

28. - E6E05

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

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

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

30. - E7A11

What type of logic defines "1" as a high voltage?

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

31. - E7B01

For what portion of a signal cycle does a Class AB amplifier operate?

Select	Answer
A	Exactly 180 degrees
B	Less than 180 degrees
C	More than 180 degrees but less than 360 degrees
D	The entire cycle

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	A notch filter
C	A band-pass filter
D	An all-pass filter

33. - E7D16

When several electrolytic filter capacitors are connected in series to increase the operating voltage of a power supply filter circuit, why should resistors be connected across each capacitor?

Select	Answer
A	To provide a safety bleeder to discharge the capacitors when the supply is off
B	To provide a minimum load current to reduce voltage excursions at light loads
C	To equalize, as much as possible, the voltage drop across each capacitor
D	All of these choices are correct

34. - E7E12

What is a frequency discriminator stage in a FM receiver?

Select	Answer
A	An automatic band-switching circuit
B	A circuit for filtering two closely adjacent signals
C	A circuit for detecting FM signals
D	An FM generator circuit

35. - E7F12

What digital process is applied to I and Q signals in order to recover the baseband modulation information?

Select	Answer
A	Quadrature mixing
B	Signal conditioning
C	Fast Fourier Transform
D	Decimation

36. - E7G08

How does the gain of an ideal operational amplifier vary with frequency?

Select	Answer
A	It decreases linearly with increasing frequency
B	It decreases logarithmically with increasing frequency
C	It does not vary with frequency
D	It increases linearly with increasing frequency

37. - E7H10

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

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

38. - E8A06

What is the approximate ratio of PEP-to-average power in a typical single-sideband phone signal?

Select	Answer
A	2.5 to 1
B	25 to 1
C	100 to 1
D	1 to 1

39. - E8B03

What is the modulation index of an FM-phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency when the modulating frequency is 1000 Hz?

Select	Answer
A	0.3
B	3
C	1000
D	3000

40. - E8C02

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

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

41. - E8D08

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

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

42. - E9A08

What is meant by antenna bandwidth?

Select	Answer
A	The angle between the half-power radiation points
B	Antenna length divided by the number of elements
C	The angle formed between two imaginary lines drawn through the element ends
D	The frequency range over which an antenna satisfies a performance requirement

43. - E9B15

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

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

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

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

46. - E9E06

What is the equivalent lumped-constant network for a hairpin matching system of a 3-element Yagi?

Select	Answer
A	Pi-L-network
B	A series capacitor
C	Pi-network
D	A shunt inductor

47. - E9F15

What impedance does a 1/2 wavelength transmission line present to a generator when the line is open at the far end?

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

48. - E9G05

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

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

49. - E9H02

Which is generally true for low band (160 meter and 80 meter) receiving antennas?

Select	Answer
A	Low loss coax transmission line is essential for good performance
B	All of these choices are correct
C	Atmospheric noise is so high that gain over a dipole is not important
D	They must be erected at least 1/2 wavelength above the ground to attain good directivity

50. - E0A04

When evaluating a site with multiple transmitters operating at the same time, the operators and licensees of which transmitters are responsible for mitigating over-exposure situations?

Select	Answer
A	Each transmitter operating with a duty-cycle greater than 50 percent
B	Only commercial transmitters
C	Only the most powerful transmitter
D	Each transmitter that produces 5 percent or more of its MPE limit at accessible locations

Figure E9-2

Figure E9-3