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

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1. - E1A01

When using a transceiver that displays the carrier frequency of phone signals, which of the following displayed frequencies represents the highest frequency at which a properly adjusted USB emission will be totally within the band?

Select	Answer
A	3 kHz below the upper band edge
B	The exact upper band edge
C	1 kHz below the upper band edge
D	300 Hz below the upper band edge

2. - E1B05

What is the National Radio Quiet Zone?

Select	Answer
A	An area in New Mexico surrounding the White Sands Test Area
B	An area surrounding the National Radio Astronomy Observatory
C	An area in Florida surrounding Cape Canaveral
D	An area in Puerto Rico surrounding the Arecibo Radio Telescope

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

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	Immediately terminate everyone's examination and close the session
C	Warn the candidate that continued failure to comply will result in termination of the examination
D	Immediately terminate the candidate's examination

6. - E1F07

When may an amateur station send a message to a business?

Select	Answer
A	When the control operator is employed by the FCC or another government agency
B	When the total money involved does not exceed $25
C	When transmitting international third-party communications
D	When neither the amateur nor his or her employer has a pecuniary interest in the communications

7. - E2A11

What type of antenna can be used to minimize the effects of spin modulation and Faraday rotation?

Select	Answer
A	A linearly polarized antenna
B	A log-periodic dipole array
C	A circularly polarized antenna
D	An isotropic antenna

8. - E2B11

What is the function of the Vertical Interval Signaling (VIS) code sent as part of an SSTV transmission?

Select	Answer
A	To provide vertical synchronization
B	To identify the call sign of the station transmitting
C	To lock the color burst oscillator in color SSTV images
D	To identify the SSTV mode being used

9. - E2C02

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

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

10. - E2D13

What type of modulation is used for JT65 contacts?

Select	Answer
A	RTTY
B	PSK
C	IEEE 802.11
D	Multi-tone AFSK

11. - E2E01

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

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

12. - E3A02

What characterizes libration fading of an EME signal?

Select	Answer
A	A slow change in the pitch of the CW signal
B	A gradual loss of signal as the Sun rises
C	The returning echo is several Hertz lower in frequency than the transmitted signal
D	A fluttery irregular fading

13. - E3B03

What is the best time of day for transequatorial propagation?

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

14. - E3C11

What does VOACAP software model?

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

15. - E4A12

Which of the following procedures is an important precaution to follow when connecting a spectrum analyzer to a transmitter output?

Select	Answer
A	All of these choices are correct
B	Use high quality double shielded coaxial cables to reduce signal losses
C	Attenuate the transmitter output going to the spectrum analyzer
D	Match the antenna to the load

16. - E4B04

If a frequency counter with a specified accuracy of +/- 0.1 ppm reads 146,520,000 Hz, what is the most the actual frequency being measured could differ from the reading?

Select	Answer
A	1.4652 kHz
B	1.4652 Hz
C	0.1 MHz
D	14.652 Hz

17. - E4C10

Which of the following is a desirable amount of selectivity for an amateur RTTY HF receiver?

Select	Answer
A	2400 Hz
B	300 Hz
C	100 Hz
D	6000 Hz

18. - E4D04

Which of the following may reduce or eliminate intermodulation interference in a repeater caused by another transmitter operating in close proximity?

Select	Answer
A	A Class D final amplifier
B	A band-pass filter in the feed line between the transmitter and receiver
C	A Class C final amplifier
D	A properly terminated circulator at the output of the transmitter

19. - E4E14

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

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

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

21. - E5B11

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 25 ohms, R is 100 ohms, and XL is 50 ohms?

Select	Answer
A	76 degrees with the voltage leading the current
B	14 degrees with the voltage lagging 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	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. - E5D16

What is the power factor of an R-L circuit having a 30 degree phase angle between the voltage and the current?

Select	Answer
A	0.866
B	0.5
C	0.577
D	1.73

24. - E6A15

Which semiconductor material contains excess holes in the outer shell of electrons?

Select	Answer
A	P-type
B	Superconductor-type
C	N-type
D	Bipolar-type

25. - E6B08

Which of the following describes a type of semiconductor diode?

Select	Answer
A	Metal-semiconductor junction
B	Electrolytic rectifier
C	CMOS-field effect
D	Thermionic emission diode

26. - E6C01

What is the function of hysteresis in a comparator?

Select	Answer
A	To allow the comparator to be used with AC input signal
B	To increase the sensitivity
C	To cause the output to change states continually
D	To prevent input noise from causing unstable output signals

27. - E6D14

Which type of slug material decreases inductance when inserted into a coil?

Select	Answer
A	Brass
B	Ferrite
C	Powdered-iron
D	Ceramic

28. - E6E01

Which of the following is true of a charge-coupled device (CCD)?

Select	Answer
A	It is a CMOS analog-to-digital converter
B	It is used in a battery charger circuit
C	Its phase shift changes rapidly with frequency
D	It samples an analog signal and passes it in stages from the input to the output

29. - E6F13

What is a liquid crystal display (LCD)?

Select	Answer
A	A display that uses a glowing liquid to remain brightly lit in dim light
B	A display utilizing a crystalline liquid and polarizing filters which becomes opaque when voltage is applied
C	A frequency-determining unit for a transmitter or receiver
D	A modern replacement for a quartz crystal oscillator which displays its fundamental frequency

30. - E7A12

What type of logic defines "0" as a high voltage?

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

31. - E7B03

Which of the following components form the output of a class D amplifier circuit?

Select	Answer
A	A matched load resistor to prevent damage by switching transients
B	A high-pass filter to compensate for low gain at low frequencies
C	A temperature compensating load resistor to improve linearity
D	A low-pass filter to remove switching signal components

32. - E7C04

How does an impedance-matching circuit transform a complex impedance to a resistive impedance?

Select	Answer
A	It introduces negative resistance to cancel the resistive part of impedance
B	Network resistances are substituted for load resistances and reactances are matched to the resistances
C	It cancels the reactive part of the impedance and changes the resistive part to a desired value
D	It introduces transconductance to cancel the reactive part of impedance

33. - E7D15

What is the purpose of a "step-start" circuit in a high voltage power supply?

Select	Answer
A	To compensate for variations of the incoming line voltage
B	To allow for remote control of the power supply
C	To provide a dual-voltage output for reduced power applications
D	To allow the filter capacitors to charge gradually

34. - E7E06

Why is de-emphasis commonly used in FM communications receivers?

Select	Answer
A	To reduce impulse noise reception
B	To remove third-order distortion products
C	For higher efficiency
D	For compatibility with transmitters using phase modulation

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

36. - E7G04

What is meant by the term op-amp input offset voltage?

Select	Answer
A	The differential input voltage needed to bring the open loop output voltage to zero
B	The difference between the output voltage of the op-amp and the input voltage required in the immediately following stage
C	The output voltage of the op-amp minus its input voltage
D	The potential between the amplifier input terminals of the op-amp in an open loop condition

37. - E7H15

Which of these functions can be performed by a phase-locked loop?

Select	Answer
A	Comparison of two digital input signals, digital pulse counter
B	Photovoltaic conversion, optical coupling
C	Frequency synthesis, FM demodulation
D	Wide-band AF and RF power amplification

38. - E8A09

How many levels can an analog-to-digital converter with 8 bit resolution encode?

Select	Answer
A	8
B	256 divided by the gain of the input amplifier
C	8 multiplied by the gain of the input amplifier
D	256

39. - E8B07

Orthogonal Frequency Division Multiplexing is a technique used for which type of amateur communication?

Select	Answer
A	EME
B	Extremely low-power contacts
C	High speed digital modes
D	OFDM signals are not allowed on amateur bands

40. - E8C09

Which is the name of a digital code where each preceding or following character changes by only one bit?

Select	Answer
A	Binary Coded Decimal Code
B	Gray code
C	Extended Binary Coded Decimal Interchange Code
D	Excess 3 code

41. - E8D01

Why are received spread spectrum signals resistant to interference?

Select	Answer
A	Signals not using the spread spectrum algorithm are suppressed in the receiver
B	If interference is detected by the receiver it will signal the transmitter to change frequencies
C	The high power used by a spread spectrum transmitter keeps its signal from being easily overpowered
D	The receiver is always equipped with a digital blanker

42. - E9A12

How much gain does an antenna have compared to a 1/2-wavelength dipole when it has 6 dB gain over an isotropic antenna?

Select	Answer
A	6.0 dB
B	8.15 dB
C	2.79 dB
D	3.85 dB

43. - E9B03

In the antenna radiation pattern shown in Figure E9-1, what is the front-to-side ratio?

Select	Answer
A	12 dB
B	14 dB
C	18 dB
D	24 dB

44. - E9C09

What is a G5RV antenna?

Select	Answer
A	A phased array antenna consisting of multiple loops
B	A multi-band dipole antenna fed with coax and a balun through a selected length of open wire transmission line
C	A wide band dipole using shorted coaxial cable for the radiating elements and fed with a 4:1 balun
D	A multi-band trap antenna

45. - E9D13

What usually occurs if a Yagi antenna is designed solely for maximum forward gain?

Select	Answer
A	The front-to-back ratio decreases
B	The SWR is reduced
C	The frequency response is widened over the whole frequency band
D	The front-to-back ratio increases

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 gamma match
B	The epsilon match
C	The stub match
D	The delta match

47. - E9F05

What is the approximate physical length of a solid polyethylene dielectric coaxial transmission line that is electrically one-quarter wavelength long at 14.1 MHz?

Select	Answer
A	20 meters
B	3.5 meters
C	0.2 meters
D	2.3 meters

48. - E9G08

What is the process of normalization with regard to a Smith chart?

Select	Answer
A	Reassigning impedance values with regard to the prime center
B	Reassigning reactance values with regard to the resistance axis
C	Reassigning prime center with regard to the reactance axis
D	Reassigning resistance values with regard to the reactance axis

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 receives equally well in all directions
C	It has a bidirectional pattern
D	It is non-rotatable

50. - E0A11

Which of the following injuries can result from using high-power UHF or microwave transmitters?

Select	Answer
A	Localized heating of the body from RF exposure in excess of the MPE limits
B	Ingestion of ozone gas from the cooling system
C	Hearing loss caused by high voltage corona discharge
D	Blood clotting from the intense magnetic field

Figure E9-1