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

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1. - E1A07

Which amateur band requires transmission on specific channels rather than on a range of frequencies?

Select	Answer
A	12 meter band
B	17 meter band
C	60 meter band
D	30 meter band

2. - E1B03

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

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

3. - E1C05

When may an automatically controlled station originate third party communications?

Select	Answer
A	Only when transmitting RTTY or data emissions
B	When approved by the National Telecommunication and Information Administration
C	When agreed upon by the sending or receiving station
D	Never

4. - E1D03

What is a telecommand station in the amateur satellite service?

Select	Answer
A	An amateur station located on the Earth's surface for communication with other Earth stations by means of Earth satellites
B	An amateur station that transmits telemetry consisting of measurements of upper atmosphere
C	An amateur station that transmits communications to initiate, modify or terminate functions of a space station
D	An amateur station located more than 50 km above the Earth's surface

5. - E1E08

To which of the following examinees may a VE not administer an examination?

Select	Answer
A	Relatives of the VE as listed in the FCC rules
B	Friends of the VE
C	Employees of the VE
D	All of these choices are correct

6. - E1F09

Which of the following conditions apply when transmitting spread spectrum emission?

Select	Answer
A	The transmission must not be used to obscure the meaning of any communication
B	A station transmitting SS emission must not cause harmful interference to other stations employing other authorized emissions
C	All of these choices are correct
D	The transmitting station must be in an area regulated by the FCC or in a country that permits SS emissions

7. - E2A07

Which of the following types of signals can be relayed through a linear transponder?

Select	Answer
A	SSB and SSTV
B	FM and CW
C	PSK and Packet
D	All of these choices are correct

8. - E2B06

What is vestigial sideband modulation?

Select	Answer
A	Amplitude modulation in which one complete sideband and a portion of the other are transmitted
B	Narrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier
C	Spread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation
D	A type of modulation in which one sideband is inverted

9. - E2C07

What is the Cabrillo format?

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

10. - E2D03

Which of the following digital modes is especially useful for EME communications?

Select	Answer
A	FSK441
B	PACTOR III
C	Olivia
D	JT65

11. - E2E03

How is the timing of JT65 contacts organized?

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

12. - E3A11

What is a typical range for tropospheric propagation of microwave signals?

Select	Answer
A	100 miles to 300 miles
B	1200 miles
C	2500 miles
D	10 miles to 50 miles

13. - E3B07

Which of the following could account for hearing an echo on the received signal of a distant station?

Select	Answer
A	Receipt of a signal by more than one path
B	Transmit frequency is higher than the MUF
C	High D layer absorption
D	Meteor scatter

14. - E3C11

What does VOACAP software model?

Select	Answer
A	AC voltage and impedance
B	AC current and impedance
C	VHF radio propagation
D	HF 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	Use high quality double shielded coaxial cables to reduce signal losses
B	Attenuate the transmitter output going to the spectrum analyzer
C	Match the antenna to the load
D	All of these choices are correct

16. - E4B02

What is an advantage of using a bridge circuit to measure impedance?

Select	Answer
A	It can display results directly in Smith chart format
B	It is very precise in obtaining a signal null
C	It is relatively immune to drift in the signal generator source
D	It provides an excellent match under all conditions

17. - E4C05

What does a value of -174 dBm/Hz represent with regard to the noise floor of a receiver?

Select	Answer
A	The galactic noise contribution to minimum detectable signal
B	The minimum detectable signal as a function of receive frequency
C	The noise figure of a 1 Hz bandwidth receiver
D	The theoretical noise at the input of a perfect receiver at room temperature

18. - E4D12

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

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

19. - E4E04

How can conducted and radiated noise caused by an automobile alternator be suppressed?

Select	Answer
A	By installing a high-pass filter in series with the radio's power lead and a low-pass filter in parallel with the field lead
B	By connecting the radio's power leads directly to the battery and by installing coaxial capacitors in line with the alternator leads
C	By installing filter capacitors in series with the DC power lead and a blocking capacitor in the field lead
D	By installing a noise suppression resistor and a blocking capacitor in both leads

20. - E5A02

What is resonance in an electrical circuit?

Select	Answer
A	The highest frequency that will pass current
B	The frequency at which the capacitive reactance equals the inductive reactance
C	The lowest frequency that will pass current
D	The frequency at which the reactive impedance equals the resistive impedance

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 leading the current
D	14.0 degrees with the voltage lagging the current

22. - E5C16

Which point on Figure E5-2 best represents the impedance of a series circuit consisting of a 300 ohm resistor and a 19 picofarad capacitor at 21.200 MHz?

Select	Answer
A	Point 8
B	Point 1
C	Point 7
D	Point 3

23. - E5D13

How much power is consumed in a circuit consisting of a 100 ohm resistor in series with a 100 ohm inductive reactance drawing 1 ampere?

Select	Answer
A	200 Watts
B	70.7 Watts
C	141.4 Watts
D	100 Watts

24. - E6A13

What do the initials CMOS stand for?

Select	Answer
A	Complementary Mica-Oxide Silicon
B	Complementary Metal-Oxide Semiconductor
C	Common Mode Oscillating System
D	Common Mode Organic Silicon

25. - E6B08

Which of the following describes a type of semiconductor diode?

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

26. - E6C09

What is a Programmable Logic Device (PLD)?

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

27. - E6D04

Which materials are commonly used as a slug core in a variable inductor?

Select	Answer
A	Ferrite and brass
B	Polystyrene and polyethylene
C	Cobalt and aluminum
D	Teflon and Delrin

28. - E6E06

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

Select	Answer
A	Plate current that is controlled by a control grid
B	Nearly infinite gain, very high input impedance, and very low output impedance
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. - E6F10

What is the most common type of photovoltaic cell used for electrical power generation?

Select	Answer
A	Cadmium Sulfide
B	Copper oxide
C	Selenium
D	Silicon

30. - E7A07

What logical operation does a NAND gate perform?

Select	Answer
A	It produces logic "0" at its output only when all inputs are logic "1"
B	It produces logic "1" at its output only when all inputs are logic "1"
C	It produces logic "0" at its output only when all inputs are logic "0"
D	It produces logic "0" at its output if some but not all inputs are logic "1"

31. - E7B06

Which of the following amplifier types reduces or eliminates even order harmonics?

Select	Answer
A	Push-push
B	Class C
C	Class AB
D	Push-pull

32. - E7C15

What is a crystal lattice filter?

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

33. - E7D03

What device is typically used as a stable reference voltage in a linear voltage regulator?

Select	Answer
A	An SCR
B	A Zener diode
C	A tunnel diode
D	A varactor diode

34. - E7E03

How does an analog phase modulator function?

Select	Answer
A	By varying the tuning of an amplifier tank circuit to produce AM signals
B	By varying the tuning of a microphone preamplifier to produce PM signals
C	By varying the tuning of an amplifier tank circuit to produce PM signals
D	By varying the tuning of a microphone preamplifier to produce AM signals

35. - E7F14

Which of the following would allow a digital signal processing filter to create a sharper filter response?

Select	Answer
A	Double-precision math routines
B	Higher data rate
C	More taps
D	Complex phasor representations

36. - E7G06

Which of the following is the most appropriate use of an op-amp active filter?

Select	Answer
A	As a low-pass filter used between a transmitter and a transmission line
B	As a high-pass filter used to block RFI at the input to receivers
C	For smoothing power supply output
D	As an audio filter in a receiver

37. - E7H06

Which of the following oscillator circuits are commonly used in VFOs?

Select	Answer
A	Negative feedback and balanced feedback
B	Colpitts and Hartley
C	Armstrong and deForest
D	Pierce and Zener

38. - E8A05

What would be the most accurate way of measuring the RMS voltage of a complex waveform?

Select	Answer
A	By measuring the voltage with a D'Arsonval meter
B	By using a grid dip meter
C	By using an absorption wave meter
D	By measuring the heating effect in a known resistor

39. - E8B11

What is digital time division multiplexing?

Select	Answer
A	Two or more signals are arranged to share discrete time slots of a data transmission
B	Two or more data streams share the same channel by transmitting time of transmission as the sub-carrier
C	Two or more data streams are assigned to discrete sub-carriers on an FM transmitter
D	Two or more signals are quadrature modulated to increase bandwidth efficiency

40. - E8C03

When performing phase shift keying, why is it advantageous to shift phase precisely at the zero crossing of the RF carrier?

Select	Answer
A	It is easier to demodulate with a conventional, non-synchronous detector
B	This results in the least possible transmitted bandwidth for the particular mode
C	All of these choices are correct
D	It improves carrier suppression

41. - E8D03

How does the spread spectrum technique of frequency hopping work?

Select	Answer
A	If interference is detected by the receiver it will signal the transmitter to change frequencies
B	The frequency of the transmitted signal is changed very rapidly according to a particular sequence also used by the receiving station
C	If interference is detected by the receiver it will signal the transmitter to wait until the frequency is clear
D	A pseudo-random binary bit stream is used to shift the phase of an RF carrier very rapidly in a particular sequence

42. - E9A16

What is the effective radiated power relative to a dipole of a repeater station with 200 watts transmitter power output, 4 dB feed line loss, 3.2 dB duplexer loss, 0.8 dB circulator loss, and 10 dBd antenna gain?

Select	Answer
A	2000 watts
B	300 watts
C	126 watts
D	317 watts

43. - E9B01

In the antenna radiation pattern shown in Figure E9-1, what is the 3 dB beam-width?

Select	Answer
A	25 degrees
B	75 degrees
C	30 degrees
D	50 degrees

44. - E9C07

What is the approximate feed point impedance at the center of a two-wire folded dipole antenna?

Select	Answer
A	72 ohms
B	450 ohms
C	300 ohms
D	50 ohms

45. - E9D02

How can linearly polarized Yagi antennas be used to produce circular polarization?

Select	Answer
A	Arrange two Yagis collinear to each other with the driven elements fed 180 degrees out of phase
B	Stack two Yagis fed 90 degrees out of phase to form an array with the respective elements in parallel planes
C	Arrange two Yagis perpendicular to each other with the driven elements at the same point on the boom fed 90 degrees out of phase
D	Stack two Yagis fed in phase to form an array with the respective elements in parallel planes

46. - E9E07

What term best describes the interactions at the load end of a mismatched transmission line?

Select	Answer
A	Velocity factor
B	Characteristic impedance
C	Dielectric constant
D	Reflection coefficient

47. - E9F08

What is the term for the ratio of the actual speed at which a signal travels through a transmission line to the speed of light in a vacuum?

Select	Answer
A	Standing wave ratio
B	Surge impedance
C	Characteristic impedance
D	Velocity factor

48. - E9G08

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

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

49. - E9H01

When constructing a Beverage antenna, which of the following factors should be included in the design to achieve good performance at the desired frequency?

Select	Answer
A	It should be one or more wavelengths long
B	It must be mounted more than 1 wavelength above ground
C	It should be configured as a four-sided loop
D	Its overall length must not exceed 1/4 wavelength

50. - E0A11

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

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

Figure E5-2

Figure E9-1