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

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1. - E1A03

With your transceiver displaying the carrier frequency of phone signals, you hear a station calling CQ on 14.349 MHz USB. Is it legal to return the call using upper sideband on the same frequency?

Select	Answer
A	No, the sideband will extend beyond the band edge
B	Yes, because the displayed frequency is within the 20 meter band
C	No, U.S. stations are not permitted to use phone emissions above 14.340 MHz
D	Yes, because you were not the station calling CQ

2. - E1B11

What is the permitted mean power of any spurious emission relative to the mean power of the fundamental emission from a station transmitter or external RF amplifier installed after January 1, 2003 and transmitting on a frequency below 30 MHZ?

Select	Answer
A	At least 63 dB below
B	At least 43 dB below
C	At least 53 dB below
D	At least 73 dB below

3. - E1C05

When may an automatically controlled station originate third party communications?

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

4. - E1D09

Which UHF amateur service bands have frequencies available for a space station?

Select	Answer
A	70 cm and 33 cm
B	33 cm and 13 cm
C	70 cm only
D	70 cm and 13 cm

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	Record the exam session on video tape for later review by the VE team
B	The exam proctor observes the applicants and reports any violations
C	Have each applicant sign an affidavit stating that all session rules were followed
D	Use a real-time video link and the Internet to connect the exam session to the observing VEs

6. - E1F09

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

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

7. - E2A03

What is the orbital period of an Earth satellite?

Select	Answer
A	The time it takes for a satellite to complete one revolution around the Earth
B	The point of maximum height of a satellite's orbit
C	The point of minimum height of a satellite's orbit
D	The time it takes for a satellite to travel from perigee to apogee

8. - E2B10

Which of the following is an acceptable bandwidth for Digital Radio Mondiale (DRM) based voice or SSTV digital transmissions made on the HF amateur bands?

Select	Answer
A	15 KHz
B	10 KHz
C	20 KHz
D	3 KHz

9. - E2C07

What is the Cabrillo format?

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

10. - E2D14

What is one advantage of using JT65 coding?

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

11. - E2E11

What is the difference between direct FSK and audio FSK?

Select	Answer
A	Direct FSK applies the data signal to the transmitter VFO
B	Direct FSK uses a DC-coupled data connection
C	Audio FSK has a superior frequency response
D	Audio FSK can be performed anywhere in the transmit chain

12. - E3A08

When a meteor strikes the Earth's atmosphere, a cylindrical region of free electrons is formed at what layer of the ionosphere?

Select	Answer
A	The E layer
B	The D layer
C	The F1 layer
D	The F2 layer

13. - E3B10

What is the cause of gray-line propagation?

Select	Answer
A	At mid-afternoon, the Sun heats the ionosphere decreasing radio wave refraction and the MUF
B	In darkness, solar absorption drops greatly while atmospheric ionization remains steady
C	At twilight and sunrise, D-layer absorption is low while E-layer and F-layer propagation remains high
D	At midday, the Sun super heats the ionosphere causing increased refraction of radio waves

14. - E3C14

Why does the radio-path horizon distance exceed the geometric horizon?

Select	Answer
A	D-region skip
B	E-region skip
C	Downward bending due to density variations in the atmosphere
D	Downward bending due to aurora refraction

15. - E4A04

What determines the upper frequency limit for a computer soundcard-based oscilloscope program?

Select	Answer
A	Amount of memory on the soundcard
B	All of these choices are correct
C	Q of the interface of the interface circuit
D	Analog-to-digital conversion speed of the soundcard

16. - E4B17

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

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

17. - E4C03

What is the term for the blocking of one FM phone signal by another, stronger FM phone signal?

Select	Answer
A	Capture effect
B	Cross-modulation interference
C	Desensitization
D	Frequency discrimination

18. - E4D03

How can intermodulation interference between two repeaters occur?

Select	Answer
A	When the signals from the transmitters are reflected in phase from airplanes passing overhead
B	When the repeaters are in close proximity and the signals cause feedback in the final amplifier of one or both transmitters
C	When the repeaters are in close proximity and the signals mix in the final amplifier of one or both transmitters
D	When the signals from the transmitters are reflected out of phase from airplanes passing overhead

19. - E4E05

How can noise from an electric motor be suppressed?

Select	Answer
A	By using a ground-fault current interrupter in the circuit used to power the motor
B	By installing a brute-force AC-line filter in series with the motor leads
C	By installing a bypass capacitor in series with the motor leads
D	By installing a high pass filter in series with the motor's power leads

20. - E5A09

How is the Q of an RLC parallel resonant circuit calculated?

Select	Answer
A	Reactance of either the inductance or capacitance multiplied by the resistance
B	Reactance of the inductance multiplied by the reactance of the capacitance
C	Reactance of either the inductance or capacitance divided by the resistance
D	Resistance divided by the reactance of either the inductance or capacitance

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. - E5C13

What coordinate system is often used to display the resistive, inductive, and/or capacitive reactance components of impedance?

Select	Answer
A	Maidenhead grid
B	Faraday grid
C	Rectangular coordinates
D	Elliptical coordinates

23. - E5D06

In what direction is the magnetic field oriented about a conductor in relation to the direction of electron flow?

Select	Answer
A	In the same direction as the current
B	In all directions; omni-directional
C	In a direction opposite to the current
D	In a direction determined by the left-hand rule

24. - E6A07

Which of the following indicates that a silicon NPN junction transistor is biased on?

Select	Answer
A	Base-to-emitter resistance of approximately 0.6 to 0.7 ohms
B	Base-to-emitter resistance of approximately 6 to 7 ohms
C	Base-to-emitter voltage of approximately 6 to 7 volts
D	Base-to-emitter voltage of approximately 0.6 to 0.7 volts

25. - E6B13

What type of bias is required for an LED to emit light?

Select	Answer
A	Inductive bias
B	Zero bias
C	Forward bias
D	Reverse bias

26. - E6C09

What is a Programmable Logic Device (PLD)?

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

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

28. - E6E01

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

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

29. - E6F10

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

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

30. - E7A06

What is a characteristic of a monostable multivibrator?

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

31. - E7B16

What is the effect of intermodulation products in a linear power amplifier?

Select	Answer
A	Low efficiency
B	Transmission of spurious signals
C	Creation of parasitic oscillations
D	All of these choices are correct

32. - E7C11

Which of the following is the common name for a filter network which is equivalent to two L-networks connected back-to-back with the two inductors in series and the capacitors in shunt at the input and output?

Select	Answer
A	Cascode
B	Omega
C	Pi-L
D	Pi

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 provide a dual-voltage output for reduced power applications
C	To allow for remote control of the power supply
D	To allow the filter capacitors to charge gradually

34. - E7E05

What circuit is added to an FM transmitter to boost the higher audio frequencies?

Select	Answer
A	A pre-emphasis network
B	An audio prescaler
C	A de-emphasis network
D	A heterodyne suppressor

35. - E7F04

What is a common method of generating an SSB signal using digital signal processing?

Select	Answer
A	Emulation of quartz crystal filter characteristics
B	Combine signals with a quadrature phase relationship
C	Mixing products are converted to voltages and subtracted by adder circuits
D	A frequency synthesizer removes the unwanted sidebands

36. - E7G09

What will be the output voltage of the circuit shown in Figure E7-4 if R1 is 1000 ohms, RF is 10,000 ohms, and 0.23 volts DC is applied to the input?

Select	Answer
A	2.3 volts
B	-0.23 volts
C	0.23 volts
D	-2.3 volts

37. - E7H07

How can an oscillator's microphonic responses be reduced?

Select	Answer
A	Use of NP0 capacitors
B	Using the oscillator only for CW and digital signals
C	Eliminating noise on the oscillator's power supply
D	Mechanically isolating the oscillator circuitry from its enclosure

38. - E8A11

What type of information can be conveyed using digital waveforms?

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

39. - E8B07

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

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

40. - E8C07

What is the necessary bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?

Select	Answer
A	15.36 kHz
B	4.8 kHz
C	9.6 kHz
D	5.76 kHz

41. - E8D05

What is the most common method of reducing key clicks?

Select	Answer
A	Increase keying waveform rise and fall times
B	High-pass filters at the transmitter output
C	Low-pass filters at the transmitter output
D	Reduce keying waveform rise and fall times

42. - E9A11

Which of the following factors determines ground losses for a ground-mounted vertical antenna operating in the 3 MHz to 30 MHz range?

Select	Answer
A	Distance from the transmitter
B	Soil conductivity
C	Take-off angle
D	The standing wave ratio

43. - E9B15

What is the front-to-back ratio of the radiation pattern shown in Figure E9-2?

Select	Answer
A	24 dB
B	3 dB
C	28 dB
D	15 dB

44. - E9C08

What is a folded dipole antenna?

Select	Answer
A	A dipole configured to provide forward gain
B	A dipole one-quarter wavelength long
C	A type of ground-plane antenna
D	A dipole consisting of one wavelength of wire forming a very thin loop

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

46. - E9E04

What is the purpose of the series capacitor in a gamma-type antenna matching network?

Select	Answer
A	To cancel the inductive reactance of the matching network
B	To provide a rejection notch that prevents the radiation of harmonics
C	To provide DC isolation between the feed line and the antenna
D	To transform the antenna impedance to a higher value

47. - E9F10

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

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

48. - E9G01

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

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

49. - E9H06

What is the triangulation method of direction finding?

Select	Answer
A	A fixed receiving station uses three different antennas to plot the location of the signal source
B	The geometric angles of sky waves from the source are used to determine its position
C	Antenna headings from several different receiving locations are used to locate the signal source
D	A fixed receiving station plots three headings to the signal source

50. - E0A08

What does SAR measure?

Select	Answer
A	Synthetic Aperture Ratio of the human body
B	Signal Amplification Rating
C	The rate at which RF energy is absorbed by the body
D	The rate of RF energy reflected from stationary terrain

Figure E7-4

Figure E9-2