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	On any frequency where the signal's sidebands are within the channel
C	At the lowest frequency of the channel
D	At the center frequency of the channel

2. - E1B03

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

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

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 identify in the official language of the country in which you are operating
C	You must append "/CEPT" to your call sign
D	The U.S. embassy must approve of your operation

4. - E1D05

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

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

5. - E1E07

What should a VE do if a candidate fails to comply with the examiner's instructions during an amateur operator license examination?

Select	Answer
A	Allow the candidate to complete the examination, but invalidate the results
B	Warn the candidate that continued failure to comply will result in termination of the examination
C	Immediately terminate everyone's examination and close the session
D	Immediately terminate the candidate's examination

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 transmitted for hire or material compensation, except as otherwise provided in the rules
C	Communications that have a religious content
D	Communications in a language other than English

7. - E2A12

What is one way to predict the location of a satellite at a given time?

Select	Answer
A	By subtracting the mean anomaly from the orbital inclination
B	By means of the Doppler data for the specified satellite
C	By adding the mean anomaly to the orbital inclination
D	By calculations using the Keplerian elements for the specified satellite

8. - E2B15

What signals SSTV receiving equipment to begin a new picture line?

Select	Answer
A	Specific tone frequencies
B	Specific tone amplitudes
C	Elapsed time
D	A two-tone signal

9. - E2C10

Why might a DX station state that they are listening on another frequency?

Select	Answer
A	Because the DX station may be transmitting on a frequency that is prohibited to some responding stations
B	To improve operating efficiency by reducing interference
C	All of these choices are correct
D	To separate the calling stations from the DX station

10. - E2D07

What digital protocol is used by APRS?

Select	Answer
A	AMTOR
B	PACTOR
C	802.11
D	AX.25

11. - E2E13

Which of the following is a possible reason that attempts to initiate contact with a digital station on a clear frequency are unsuccessful?

Select	Answer
A	The protocol version you are using is not the supported by the digital station
B	Another station you are unable to hear is using the frequency
C	All of these choices are correct
D	Your transmit frequency is incorrect

12. - E3A03

When scheduling EME contacts, which of these conditions will generally result in the least path loss?

Select	Answer
A	When the Moon is full
B	When the Moon is at apogee
C	When the Moon is at perigee
D	When the MUF is above 30 MHz

13. - E3B02

What is the approximate maximum range for signals using transequatorial propagation?

Select	Answer
A	2500 miles
B	1000 miles
C	7500 miles
D	5000 miles

14. - E3C11

What does VOACAP software model?

Select	Answer
A	VHF radio propagation
B	AC voltage and impedance
C	HF propagation
D	AC current and impedance

15. - E4A11

Which of the following is good practice when using an oscilloscope probe?

Select	Answer
A	Never use a high impedance probe to measure a low impedance circuit
B	All of these choices are correct
C	Keep the signal ground connection of the probe as short as possible
D	Never use a DC-coupled probe to measure an AC circuit

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

17. - E4C09

Which of the following choices is a good reason for selecting a high frequency for the design of the IF in a conventional HF or VHF communications receiver?

Select	Answer
A	Reduced drift
B	Easier for front-end circuitry to eliminate image responses
C	Fewer components in the receiver
D	Improved receiver noise figure

18. - E4D13

Which of the following can cause receiver desensitization?

Select	Answer
A	Audio gain adjusted too low
B	Audio bias adjusted too high
C	Squelch gain misadjusted
D	Strong adjacent channel signals

19. - E4E09

What undesirable effect can occur when using an IF noise blanker?

Select	Answer
A	The audio frequency bandwidth of the received signal might be compressed
B	Nearby signals may appear to be excessively wide even if they meet emission standards
C	Received audio in the speech range might have an echo effect
D	FM signals can no longer be demodulated

20. - E5A04

What is the magnitude of the impedance of a circuit with a resistor, an inductor and a capacitor all in parallel, at resonance?

Select	Answer
A	Approximately equal to circuit resistance
B	Approximately equal to capacitive reactance
C	Low, as compared to the circuit resistance
D	Approximately equal to inductive reactance

21. - E5B07

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 500 ohms, R is 1 kilohm, and XL is 250 ohms?

Select	Answer
A	68.2 degrees with the voltage leading the current
B	68.2 degrees with the voltage lagging the current
C	14.0 degrees with the voltage lagging the current
D	14.0 degrees with the voltage leading the current

22. - E5C06

What does the impedance 50-j25 represent?

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

23. - E5D09

What happens to reactive power in an AC circuit that has both ideal inductors and ideal capacitors?

Select	Answer
A	It is dissipated as heat in the circuit
B	It is repeatedly exchanged between the associated magnetic and electric fields, but is not dissipated
C	It is dissipated in the formation of inductive and capacitive fields
D	It is dissipated as kinetic energy in the circuit

24. - E6A09

What is a depletion-mode FET?

Select	Answer
A	Any FET for which holes are the majority carriers
B	An FET that has no current flow between source and drain when no gate voltage is applied
C	An FET that exhibits a current flow between source and drain when no gate voltage is applied
D	Any FET without a channel

25. - E6B02

What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

Select	Answer
A	Much higher reverse voltage breakdown
B	Less forward voltage drop
C	Enhanced carrier retention time
D	Controlled reverse avalanche voltage

26. - E6C02

What happens when the level of a comparator's input signal crosses the threshold?

Select	Answer
A	The comparator enters latch-up
B	The IC input can be damaged
C	The feedback loop becomes unstable
D	The comparator changes its output state

27. - E6D07

What is the usable frequency range of inductors that use toroidal cores, assuming a correct selection of core material for the frequency being used?

Select	Answer
A	From a few kHz to no more than 30 MHz
B	From less than 20 Hz to approximately 300 MHz
C	From approximately 10 Hz to no more than 3000 kHz
D	From about 100 kHz to at least 1000 GHz

28. - E6E10

What is the packaging technique in which leadless components are soldered directly to circuit boards?

Select	Answer
A	Direct soldering
B	Surface mount
C	Virtual lead mounting
D	Stripped lead

29. - E6F04

What is the photovoltaic effect?

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

30. - E7A09

What logical operation is performed by an exclusive NOR gate?

Select	Answer
A	It produces logic "0" at its output only if all inputs are logic "0"
B	It produces logic "1" at its output only if all inputs are logic "1"
C	It produces logic "0" at its output if any single input is logic "1"
D	It produces logic "1" at its output if any single input is logic "1"

31. - E7B02

What is a Class D amplifier?

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

32. - E7C03

What advantage does a Pi-L-network have over a regular Pi-network for impedance matching between the final amplifier of a vacuum-tube transmitter and an antenna?

Select	Answer
A	Greater harmonic suppression
B	Greater transformation range
C	Higher efficiency
D	Lower losses

33. - E7D07

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

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

34. - E7E07

What is meant by the term baseband in radio communications?

Select	Answer
A	The unmodulated bandwidth of the transmitted signal
B	The lowest frequency band that the transmitter or receiver covers
C	The frequency components present in the modulating signal
D	The basic oscillator frequency in an FM transmitter that is multiplied to increase the deviation and carrier frequency

35. - E7F01

What is meant by direct digital conversion as applied to software defined radios?

Select	Answer
A	Incoming RF is converted to a control voltage for a voltage controlled oscillator
B	A switching mixer is used to generate I and Q signals directly from the RF input
C	Software is converted from source code to object code during operation of the receiver
D	Incoming RF is digitized by an analog-to-digital converter without being mixed with a local oscillator signal

36. - E7G01

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

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

37. - E7H12

Which of the following must be done to insure that a crystal oscillator provides the frequency specified by the crystal manufacturer?

Select	Answer
A	Provide the crystal with a specified parallel inductance
B	Provide the crystal with a specified parallel capacitance
C	Bias the crystal at a specified voltage
D	Bias the crystal at a specified current

38. - E8A11

What type of information can be conveyed using digital waveforms?

Select	Answer
A	Human speech
B	Data
C	All of these choices are correct
D	Video signals

39. - E8B01

What is the term for the ratio between the frequency deviation of an RF carrier wave and the modulating frequency of its corresponding FM-phone signal?

Select	Answer
A	Percentage of modulation
B	Modulation index
C	Quieting index
D	FM compressibility

40. - E8C01

How is Forward Error Correction implemented?

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

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

42. - E9A17

What is the effective radiated power of a repeater station with 200 watts transmitter power output, 2 dB feed line loss, 2.8 dB duplexer loss, 1.2 dB circulator loss, and 7 dBi antenna gain?

Select	Answer
A	252 watts
B	159 watts
C	63.2 watts
D	632 watts

43. - E9B12

What is the far field of an antenna?

Select	Answer
A	The region where radiated field strengths are obstructed by objects of reflection
B	The region where the shape of the antenna pattern is independent of distance
C	The region where radiated power dissipates over a specified time period
D	The region of the ionosphere where radiated power is not refracted

44. - E9C12

Which of the following describes an extended double Zepp antenna?

Select	Answer
A	A wideband vertical antenna constructed from precisely tapered aluminum tubing
B	A portable antenna erected using two push support poles
C	A center fed 1.25 wavelength antenna (two 5/8 wave elements in phase)
D	An end fed folded dipole antenna

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

46. - E9E13

What is a use for a Wilkinson divider?

Select	Answer
A	It is used to divide power equally between two 50 ohm loads while maintaining 50 ohm input impedance
B	It is used to feed low-impedance loads from a high-impedance source
C	It divides the operating frequency of a transmitter signal so it can be used on a lower frequency band
D	It is used to feed high-impedance antennas from a low-impedance source

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

48. - E9G04

What are the two families of circles and arcs that make up a Smith chart?

Select	Answer
A	Resistance and reactance
B	Resistance and voltage
C	Voltage and impedance
D	Reactance and voltage

49. - E9H04

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

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

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

Figure E7-3