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

Logging in (or registering) will help the system to select questions that you need to focus on.

1. - E1A10

If an amateur station is installed aboard a ship or aircraft, what condition must be met before the station is operated?

Select	Answer
A	Its operation must be approved by the master of the ship or the pilot in command of the aircraft
B	The amateur station operator must agree not to transmit when the main radio of the ship or aircraft is in use
C	The amateur operator must have an FCC Marine or Aircraft endorsement on his or her amateur license
D	The amateur station must have a power supply that is completely independent of the main ship or aircraft power supply

2. - E1B07

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

Select	Answer
A	0.5
B	3.0
C	2.0
D	1.0

3. - E1C02

What is meant by automatic control of a station?

Select	Answer
A	Remotely controlling a station's antenna pattern through a directional control link
B	The use of a control link between a control point and a locally controlled station
C	The use of devices and procedures for control so that the control operator does not have to be present at a control point
D	A station operating with its output power controlled automatically

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 within 50 km of the Earth's surface intended for communications with amateur stations by means of objects in space
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	The exam proctor observes the applicants and reports any violations
D	Record the exam session on video tape for later review by the VE team

6. - E1F02

What privileges are authorized in the U.S. to persons holding an amateur service license granted by the Government of Canada?

Select	Answer
A	Full privileges, up to and including those of the Extra Class License, on the 80, 40, 20, 15, and 10 meter bands
B	All privileges of the Extra Class license
C	The operating terms and conditions of the Canadian amateur service license, not to exceed U.S. Extra Class privileges
D	None, they must obtain a U.S. license

7. - E2A09

What do the terms L band and S band specify with regard to satellite communications?

Select	Answer
A	FM and Digital Store-and-Forward systems
B	The 2 meter and 70 centimeter bands
C	The 23 centimeter and 13 centimeter bands
D	Which sideband to use

8. - E2B13

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

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

9. - E2C02

Which of the following best describes the term self-spotting in regards to HF contest operating?

Select	Answer
A	An automatic method for rapidly zero beating or tuning to a station's frequency before calling that station
B	A manual technique for rapidly zero beating or tuning to a station's frequency before calling that station
C	The acceptable practice of manually posting the call signs of stations on a spotting network
D	The generally prohibited practice of posting one's own call sign and frequency on a spotting network

10. - E2D10

How can an APRS station be used to help support a public service communications activity?

Select	Answer
A	An APRS station with a GPS unit can automatically transmit information to show a mobile station's position during the event
B	All of these choices are correct
C	An APRS station with an emergency medical technician can automatically transmit medical data to the nearest hospital
D	APRS stations with General Personnel Scanners can automatically relay the participant numbers and time as they pass the check points

11. - E2E03

How is the timing of JT65 contacts organized?

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

12. - E3A07

Atmospheric ducts capable of propagating microwave signals often form over what geographic feature?

Select	Answer
A	Urban areas
B	Forests
C	Mountain ranges
D	Bodies of water

13. - E3B01

What is transequatorial propagation?

Select	Answer
A	Propagation between two stations at the same latitude
B	Propagation between two mid-latitude points at approximately the same distance north and south of the magnetic equator
C	Propagation between any two points located on the magnetic equator
D	Propagation between two continents by way of ducts along the magnetic equator

14. - E3C04

What does the value of Bz (B sub Z) represent?

Select	Answer
A	Duration of long-delayed echoes
B	Geomagnetic field stability
C	Critical frequency for vertical transmissions
D	Direction and strength of the interplanetary magnetic field

15. - E4A10

Which of the following displays multiple digital signal states simultaneously?

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

16. - E4B13

Which S parameter is equivalent to forward gain?

Select	Answer
A	S11
B	S22
C	S12
D	S21

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	-155 dBm
B	-148 dBm
C	-174 dBm
D	-164 dBm

18. - E4D07

Which describes the most significant effect of an off-frequency signal when it is causing cross-modulation interference to a desired signal?

Select	Answer
A	A reduction in apparent signal strength
B	A large increase in background noise
C	The desired signal can no longer be heard
D	The off-frequency unwanted signal is heard in addition to the desired signal

19. - E4E14

What is one type of electrical interference that might be caused by the operation of a nearby personal computer?

Select	Answer
A	The appearance of unstable modulated or unmodulated signals at specific frequencies
B	A clicking noise at intervals of a few seconds
C	A loud AC hum in the audio output of your station receiver
D	A whining type noise that continually pulses off and on

20. - E5A07

What is the magnitude of the current at the input of a parallel RLC circuit at resonance?

Select	Answer
A	Maximum
B	R/L
C	L/R
D	Minimum

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

22. - E5C03

Which of the following represents an inductive reactance in polar coordinates?

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

23. - E5D17

How many watts are consumed in a circuit having a power factor of 0.6 if the input is 200VAC at 5 amperes?

Select	Answer
A	200 watts
B	600 watts
C	1600 watts
D	1000 watts

24. - E6A03

Why does a PN-junction diode not conduct current when reverse biased?

Select	Answer
A	Excess holes in P-type material combine with the electrons in N-type material, converting the entire diode into an insulator
B	Only N-type semiconductor material can conduct current
C	Holes in P-type material and electrons in the N-type material are separated by the applied voltage, widening the depletion region
D	Only P-type semiconductor material can conduct current

25. - E6B04

What type of semiconductor device is designed for use as a voltage-controlled capacitor?

Select	Answer
A	Tunnel diode
B	Silicon-controlled rectifier
C	Zener diode
D	Varactor diode

26. - E6C13

Which of the following is an advantage of BiCMOS logic?

Select	Answer
A	It has the high input impedance of CMOS and the low output impedance of bipolar transistors
B	Its simplicity results in much less expensive devices than standard CMOS
C	All of these choices are correct
D	It is totally immune to electrostatic damage

27. - E6D10

What is a primary advantage of using a toroidal core instead of a solenoidal core in an inductor?

Select	Answer
A	Toroidal cores have lower Q characteristics
B	Toroidal cores exhibit greater hysteresis
C	Toroidal cores make it easier to couple the magnetic energy into other components
D	Toroidal cores confine most of the magnetic field within the core material

28. - E6E12

Why are high-power RF amplifier ICs and transistors sometimes mounted in ceramic packages?

Select	Answer
A	Enhanced sensitivity to light
B	Better dissipation of heat
C	High-voltage insulating ability
D	To provide a low-pass frequency response

29. - E6F03

What is the most common configuration of an optoisolator or optocoupler?

Select	Answer
A	A lens and a photomultiplier
B	An LED and a phototransistor
C	An amplitude modulated helium-neon laser
D	A frequency modulated helium-neon laser

30. - E7A01

Which is a bi-stable circuit?

Select	Answer
A	An "OR" gate
B	An "AND" gate
C	A clock
D	A flip-flop

31. - E7B04

Where on the load line of a Class A common emitter amplifier would bias normally be set?

Select	Answer
A	At a point where the load line intersects the zero bias current curve
B	At a point where the bias resistor equals the load resistor
C	Where the load line intersects the voltage axis
D	Approximately half-way between saturation and cutoff

32. - E7C15

What is a crystal lattice filter?

Select	Answer
A	A power supply filter made with interlaced quartz crystals
B	A filter with wide bandwidth and shallow skirts made using quartz crystals
C	An audio filter made with four quartz crystals that resonate at 1kHz intervals
D	A filter with narrow bandwidth and steep skirts made using quartz crystals

33. - E7D05

Which of the following types of linear voltage regulator places a constant load on the unregulated voltage source?

Select	Answer
A	A constant current source
B	A shunt current source
C	A series regulator
D	A shunt regulator

34. - E7E09

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

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

35. - E7F05

How frequently must an analog signal be sampled by an analog-to-digital converter so that the signal can be accurately reproduced?

Select	Answer
A	At the same rate as the highest frequency component of the signal
B	At half the rate of the highest frequency component of the signal
C	At four times the rate of the highest frequency component of the signal
D	At twice the rate of the highest frequency component of the signal

36. - E7G07

What magnitude of voltage gain can be expected from the circuit in Figure E7-4 when R1 is 10 ohms and RF is 470 ohms?

Select	Answer
A	94
B	24
C	0.21
D	47

37. - E7H14

What is a phase-locked loop circuit?

Select	Answer
A	An electronic circuit consisting of a precision push-pull amplifier with a differential input
B	An electronic servo loop consisting of a ratio detector, reactance modulator, and voltage-controlled oscillator
C	An electronic circuit also known as a monostable multivibrator
D	An electronic servo loop consisting of a phase detector, a low-pass filter, a voltage-controlled oscillator, and a stable reference oscillator

38. - E8A01

What is the name of the process that shows that a square wave is made up of a sine wave plus all of its odd harmonics?

Select	Answer
A	Numerical analysis
B	Differential analysis
C	Fourier analysis
D	Vector analysis

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. - E8C01

How is Forward Error Correction implemented?

Select	Answer
A	By the receiving station repeating each block of three data characters
B	By transmitting extra data that may be used to detect and correct transmission errors
C	By transmitting a special algorithm to the receiving station along with the data characters
D	By varying the frequency shift of the transmitted signal according to a predefined algorithm

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	Low-pass filters at the transmitter output
D	Increase keying waveform rise and fall times

42. - E9A13

How much gain does an antenna have compared to a 1/2-wavelength dipole when it has 12 dB gain over an isotropic antenna?

Select	Answer
A	9.85 dB
B	12.5 dB
C	14.15 dB
D	6.17 dB

43. - E9B14

What type of information can be obtained by submitting the details of a proposed new antenna to a modeling program?

Select	Answer
A	All of these choices are correct
B	Polar plots of the far field elevation and azimuth patterns
C	Antenna gain
D	SWR vs frequency charts

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 reduces low-angle radiation
C	It changes the impedance angle of the matching network
D	It reduces losses in the radiating portion of the antenna

45. - E9D05

What is a disadvantage of using a multiband trapped antenna?

Select	Answer
A	It must be neutralized
B	It radiates the harmonics and fundamental equally well
C	It might radiate harmonics
D	It is too sharply directional at lower frequencies

46. - E9E06

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

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

47. - E9F11

What impedance does a 1/8 wavelength transmission line present to a generator when the line is open at the far end?

Select	Answer
A	An inductive reactance
B	The same as the input impedance of the final generator stage
C	A capacitive reactance
D	The same as the characteristic impedance of the line

48. - E9G06

On the Smith chart shown in Figure E9-3, what is the name for the large outer circle on which the reactance arcs terminate?

Select	Answer
A	Polar axis
B	Reactance axis
C	Prime axis
D	Impedance axis

49. - E9H09

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

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

50. - E0A10

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

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

Figure E7-4

Figure E9-3