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

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1. - E1A06

Where must the carrier frequency of a CW signal be set to comply with FCC rules for 60 meter operation?

Select	Answer
A	At the highest frequency of the channel
B	At the center frequency of the channel
C	On any frequency where the signal's sidebands are within the channel
D	At the lowest frequency of the channel

2. - E1B03

Within what distance must an amateur station protect an FCC monitoring facility from harmful interference?

Select	Answer
A	10 miles
B	1 mile
C	3 miles
D	30 miles

3. - E1C13

Which of the following is required in order to operate in accordance with CEPT rules in foreign countries where permitted?

Select	Answer
A	You must bring a copy of FCC Public Notice DA 11-221
B	You must append "/CEPT" to your call sign
C	The U.S. embassy must approve of your operation
D	You must identify in the official language of the country in which you are operating

4. - E1D05

What class of licensee is authorized to be the control operator of a space station?

Select	Answer
A	Only General, Advanced or Amateur Extra Class
B	Any class with appropriate operator privileges
C	All except Technician Class
D	Only Amateur Extra Class

5. - E1E09

What may be the penalty for a VE who fraudulently administers or certifies an examination?

Select	Answer
A	A sentence of up to one year in prison
B	All of these choices are correct
C	A fine of up to $1000 per occurrence
D	Revocation of the VE's amateur station license grant and the suspension of the VE's amateur operator license grant

6. - E1F06

Under what circumstances might the FCC issue a Special Temporary Authority (STA) to an amateur station?

Select	Answer
A	To provide for experimental amateur communications
B	To provide additional spectrum for personal use
C	To allow regular operation on Land Mobile channels
D	To provide temporary operation while awaiting normal licensing

7. - E2A09

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

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

8. - E2B04

What is blanking in a video signal?

Select	Answer
A	Synchronization of the horizontal and vertical sync pulses
B	Transmitting a black and white test pattern
C	Turning off the scanning beam at the conclusion of a transmission
D	Turning off the scanning beam while it is traveling from right to left or from bottom to top

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

11. - E2E08

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

Select	Answer
A	Hellschreiber
B	PACTOR
C	AMTOR
D	RTTY

12. - E3A13

Which emission mode is best for aurora propagation?

Select	Answer
A	SSB
B	CW
C	FM
D	RTTY

13. - E3B03

What is the best time of day for transequatorial propagation?

Select	Answer
A	Noon
B	Late at night
C	Morning
D	Afternoon or early evening

14. - E3C02

What is indicated by a rising A or K index?

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

15. - E4A03

Which of the following test instrument is used to display spurious signals and/or intermodulation distortion products in an SSB transmitter?

Select	Answer
A	A time-domain reflectometer
B	A spectrum analyzer
C	A wattmeter
D	A logic analyzer

16. - E4B17

What three test loads are used to calibrate a standard RF vector network analyzer?

Select	Answer
A	Short circuit, open circuit, and 50 ohms
B	Short circuit, open circuit, and resonant circuit
C	50 ohms, 75 ohms, and 90 ohms
D	50 ohms through 1/8 wavelength, 1/4 wavelength, and 1/2 wavelength of coaxial cable

17. - E4C15

What is usually the primary source of noise that is heard from an HF receiver with an antenna connected?

Select	Answer
A	Receiver front-end noise
B	Atmospheric noise
C	Induction motor noise
D	Detector noise

18. - E4D12

What is the term for the reduction in receiver sensitivity caused by a strong signal near the received frequency?

Select	Answer
A	Cross-modulation interference
B	Quieting
C	Squelch gain rollback
D	Desensitization

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

20. - E5A08

What is the phase relationship between the current through and the voltage across a series resonant circuit at resonance?

Select	Answer
A	The voltage leads the current by 90 degrees
B	The voltage and current are in phase
C	The voltage and current are 180 degrees out of phase
D	The current leads the voltage by 90 degrees

21. - E5B09

What is the relationship between the current through a capacitor and the voltage across a capacitor?

Select	Answer
A	Voltage and current are in phase
B	Voltage leads current by 90 degrees
C	Voltage and current are 180 degrees out of phase
D	Current leads voltage by 90 degrees

22. - E5C09

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

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

23. - E5D07

What determines the strength of the magnetic field around a conductor?

Select	Answer
A	The diameter of the conductor
B	The ratio of the current to the resistance
C	The amount of current flowing through the conductor
D	The resistance divided by the current

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	Holes in P-type material and electrons in the N-type material are separated by the applied voltage, widening the depletion region
C	Only N-type semiconductor material can conduct current
D	Only P-type semiconductor material can conduct current

25. - E6B05

What characteristic of a PIN diode makes it useful as an RF switch or attenuator?

Select	Answer
A	Reverse bias controls its forward voltage drop
B	A large region of intrinsic material
C	Extremely high reverse breakdown voltage
D	Ability to dissipate large amounts of power

26. - E6C09

What is a Programmable Logic Device (PLD)?

Select	Answer
A	A device to control industrial equipment
B	Programmable equipment used for testing digital logic integrated circuits
C	A programmable collection of logic gates and circuits in a single integrated circuit
D	An algorithm for simulating logic functions during circuit design

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	229 turns
B	2 turns
C	43 turns
D	4 turns

28. - E6E06

What characteristics of the MMIC make it a popular choice for VHF through microwave circuits?

Select	Answer
A	Nearly infinite gain, very high input impedance, and very low output impedance
B	Plate current that is controlled by a control grid
C	Controlled gain, low noise figure, and constant input and output impedance over the specified frequency range
D	The ability to retrieve information from a single signal even in the presence of other strong signals

29. - E6F03

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

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

30. - E7A06

What is a characteristic of a monostable multivibrator?

Select	Answer
A	It switches momentarily to the opposite binary state and then returns to its original state after a set time
B	It produces a continuous square wave oscillating between 1 and 0
C	It stores one bit of data in either a 0 or 1 state
D	It maintains a constant output voltage, regardless of variations in the input voltage

31. - E7B11

In Figure E7-1, what is the purpose of R3?

Select	Answer
A	Fixed bias
B	Emitter bypass
C	Output load resistor
D	Self bias

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 Phase Inverter Load network
B	A network with only three discrete parts
C	A matching network in which all components are isolated from ground
D	A Pi-network with an additional series inductor on the output

33. - E7D07

What is the purpose of C2 in the circuit shown in Figure E7-3?

Select	Answer
A	It is a brute force filter for the output
B	To provide fixed DC bias for Q1
C	To self-resonate at the hum frequency
D	It bypasses hum around D1

34. - E7E08

What are the principal frequencies that appear at the output of a mixer circuit?

Select	Answer
A	The two input frequencies along with their sum and difference frequencies
B	1.414 and 0.707 times the input frequency
C	Two and four times the original frequency
D	The sum, difference and square root of the input frequencies

35. - E7F06

What is the minimum number of bits required for an analog-to-digital converter to sample a signal with a range of 1 volt at a resolution of 1 millivolt?

Select	Answer
A	8 bits
B	6 bits
C	10 bits
D	4 bits

36. - E7G10

What absolute voltage gain can be expected from the circuit in Figure E7-4 when R1 is 1800 ohms and RF is 68 kilohms?

Select	Answer
A	0.03
B	38
C	76
D	1

37. - E7H09

What type of frequency synthesizer circuit uses a phase accumulator, lookup table, digital to analog converter, and a low-pass anti-alias filter?

Select	Answer
A	A diode-switching matrix synthesizer
B	A hybrid synthesizer
C	A direct digital synthesizer
D	A phase locked loop synthesizer

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	Differential analysis
B	Vector analysis
C	Fourier analysis
D	Numerical analysis

39. - E8B04

What is the modulation index of an FM-phone signal having a maximum carrier deviation of plus or minus 6 kHz when modulated with a 2 kHz modulating frequency?

Select	Answer
A	3
B	1/3
C	6000
D	2000

40. - E8C10

What is an advantage of Gray code in digital communications where symbols are transmitted as multiple bits

Select	Answer
A	It has more resolution than simple binary
B	It increases security
C	It facilitates error detection
D	It has more possible states than simple binary

41. - E8D02

What spread spectrum communications technique uses a high speed binary bit stream to shift the phase of an RF carrier?

Select	Answer
A	Binary phase-shift keying
B	Frequency hopping
C	Direct sequence
D	Phase compandored spread spectrum

42. - E9A07

What is meant by antenna gain?

Select	Answer
A	The ratio of the radiated signal strength of an antenna in the direction of maximum radiation to that of a reference antenna
B	The final amplifier gain minus the transmission line losses
C	The ratio of the amount of power radiated by an antenna compared to the transmitter output power
D	The ratio of the signal in the forward direction to that in the opposite direction

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

45. - E9D04

Why should an HF mobile antenna loading coil have a high ratio of reactance to resistance?

Select	Answer
A	To minimize the Q
B	To minimize losses
C	To maximize losses
D	To swamp out harmonics

46. - E9E10

Which of these choices is an effective way to match an antenna with a 100 ohm feed point impedance to a 50 ohm coaxial cable feed line?

Select	Answer
A	Insert a 1/2 wavelength piece of 300 ohm twin-lead in series between the antenna terminals and the 50 ohm feed cable
B	Insert a 1/4-wavelength piece of 75 ohm coaxial cable transmission line in series between the antenna terminals and the 50 ohm feed cable
C	Connect 1/2 wavelength shorted stub of 75 ohm cable in parallel with the 50 ohm cable where it attaches to the antenna
D	Connect a 1/4-wavelength open stub of 300 ohm twin-lead in parallel with the coaxial feed line where it connects to the antenna

47. - E9F16

Which of the following is a significant difference between foam dielectric coaxial cable and solid dielectric cable, assuming all other parameters are the same?

Select	Answer
A	Foam dielectric has lower loss per unit of length
B	Foam dielectric has higher velocity factor
C	All of these choices are correct
D	Foam dielectric has lower safe operating voltage limits

48. - E9G01

Which of the following can be calculated using a Smith chart?

Select	Answer
A	Impedance along transmission lines
B	Radio propagation
C	Radiation resistance
D	Antenna radiation pattern

49. - E9H08

What is the function of a sense antenna?

Select	Answer
A	It provides diversity reception that cancels multipath signals
B	It allows DF antennas to receive signals at different vertical angles
C	It increases the sensitivity of a DF antenna array
D	It modifies the pattern of a DF antenna array to provide a null in one direction

50. - E0A09

Which insulating material commonly used as a thermal conductor for some types of electronic devices is extremely toxic if broken or crushed and the particles are accidentally inhaled?

Select	Answer
A	Uranium Hexafluoride
B	Zinc oxide
C	Beryllium Oxide
D	Mica

Figure E7-1

Figure E7-3

Figure E7-4

Figure E9-2