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

Logging in (or registering) will help the system to select questions that you need to focus on.

1. - E1A05

What is the maximum power output permitted on the 60 meter band?

Select	Answer
A	50 watts PEP effective radiated power relative to a dipole
B	50 watts PEP effective radiated power relative to an isotropic radiator
C	100 watts PEP effective radiated power relative to an isotropic radiator
D	100 watts PEP effective radiated power relative to the gain of a half-wave dipole

2. - E1B04

What must be done before placing an amateur station within an officially designated wilderness area or wildlife preserve, or an area listed in the National Register of Historical Places?

Select	Answer
A	A letter of intent must be filed with the National Audubon Society
B	A form FSD-15 must be submitted to the Department of the Interior
C	An Environmental Assessment must be submitted to the FCC
D	A proposal must be submitted to the National Park Service

3. - E1C09

Which of these ranges of frequencies is available for an automatically controlled repeater operating below 30 MHz?

Select	Answer
A	18.110 MHz - 18.168 MHz
B	24.940 MHz - 24.990 MHz
C	29.500 MHz - 29.700 MHz
D	10.100 MHz - 10.150 MHz

4. - E1D09

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

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

5. - E1E06

Who is responsible for the proper conduct and necessary supervision during an amateur operator license examination session?

Select	Answer
A	The FCC
B	The VE session manager
C	Each administering VE
D	The VEC coordinating the session

6. - E1F09

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

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

7. - E2A14

What technology is used to track, in real time, balloons carrying amateur radio transmitters?

Select	Answer
A	APRS
B	Doppler shift of beacon signals
C	Bandwidth compressed LORAN
D	Radar

8. - E2B07

What is the name of the signal component that carries color information in NTSC video?

Select	Answer
A	Luminance
B	Chroma
C	Hue
D	Spectral Intensity

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	All of these choices are correct
C	To improve operating efficiency by reducing interference
D	To separate the calling stations from the DX station

10. - E2D07

What digital protocol is used by APRS?

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

11. - E2E07

What is the typical bandwidth of a properly modulated MFSK16 signal?

Select	Answer
A	550 Hz
B	316 Hz
C	2.16 kHz
D	31 Hz

12. - E3A14

From the contiguous 48 states, in which approximate direction should an antenna be pointed to take maximum advantage of aurora propagation?

Select	Answer
A	South
B	East
C	North
D	West

13. - E3B08

What type of HF propagation is probably occurring if radio signals travel along the terminator between daylight and darkness?

Select	Answer
A	Sporadic-E
B	Transequatorial
C	Gray-line
D	Long-path

14. - E3C05

What orientation of Bz (B sub z) increases the likelihood that incoming particles from the Sun will cause disturbed conditions?

Select	Answer
A	Northward
B	Eastward
C	Westward
D	Southward

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

16. - E4B05

If a frequency counter with a specified accuracy of +/- 10 ppm reads 146,520,000 Hz, what is the most the actual frequency being measured could differ from the reading?

Select	Answer
A	10 Hz
B	146.52 Hz
C	1465.20 Hz
D	146.52 kHz

17. - E4C03

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

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

18. - E4D12

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

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

19. - E4E05

How can noise from an electric motor be suppressed?

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

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

22. - E5C01

Which of the following represents a capacitive reactance in rectangular notation?

Select	Answer
A	X
B	-jX
C	+jX
D	Omega

23. - E5D07

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

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

24. - E6A12

Why do many MOSFET devices have internally connected Zener diodes on the gates?

Select	Answer
A	To keep the gate voltage within specifications and prevent the device from overheating
B	To provide a voltage reference for the correct amount of reverse-bias gate voltage
C	To reduce the chance of the gate insulation being punctured by static discharges or excessive voltages
D	To protect the substrate from excessive voltages

25. - E6B06

Which of the following is a common use of a hot-carrier diode?

Select	Answer
A	As a VHF/UHF mixer or detector
B	As balanced mixers in FM generation
C	As a variable capacitance in an automatic frequency control circuit
D	As a constant voltage reference in a power supply

26. - E6C02

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

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

27. - E6D14

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

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

28. - E6E12

Why are high-power RF amplifier ICs and transistors sometimes mounted in ceramic packages?

Select	Answer
A	High-voltage insulating ability
B	Enhanced sensitivity to light
C	Better dissipation of heat
D	To provide a low-pass frequency response

29. - E6F03

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

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

30. - E7A11

What type of logic defines "1" as a high voltage?

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

31. - E7B11

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

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

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	Lower losses
C	Greater transformation range
D	Higher efficiency

33. - E7D06

What is the purpose of Q1 in the circuit shown in Figure E7-3?

Select	Answer
A	It provides negative feedback to improve regulation
B	It increases the current-handling capability of the regulator
C	It provides a constant load for the voltage source
D	It provides D1 with current

34. - E7E10

How does a diode detector function?

Select	Answer
A	By rectification and filtering of RF signals
B	By mixing signals with noise in the transition region of the diode
C	By breakdown of the Zener voltage
D	By sensing the change of reactance in the diode with respect to frequency

35. - E7F10

What aspect of receiver analog-to-digital conversion determines the maximum receive bandwidth of a Direct Digital Conversion SDR?

Select	Answer
A	Sample rate
B	Sample width in bits
C	Processor latency
D	Sample clock phase noise

36. - E7G05

How can unwanted ringing and audio instability be prevented in a multi-section op-amp RC audio filter circuit?

Select	Answer
A	Restrict gain but increase Q
B	Increase both gain and Q
C	Restrict both gain and Q
D	Restrict Q but increase gain

37. - E7H01

What are three oscillator circuits used in Amateur Radio equipment?

Select	Answer
A	Taft, Hartley and Pierce
B	Taft, Pierce and negative feedback
C	Colpitts, Hartley and Pierce
D	Pierce, Fenner and Beane

38. - E8A03

What type of wave does a Fourier analysis show to be made up of sine waves of a given fundamental frequency plus all of its harmonics?

Select	Answer
A	A square wave
B	A sawtooth wave
C	A sine wave
D	A cosine wave

39. - E8B03

What is the modulation index of an FM-phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency when the modulating frequency is 1000 Hz?

Select	Answer
A	1000
B	0.3
C	3000
D	3

40. - E8C05

What is the necessary bandwidth of a 13-WPM international Morse code transmission?

Select	Answer
A	Approximately 26 Hz
B	Approximately 13 Hz
C	Approximately 52 Hz
D	Approximately 104 Hz

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 receiver is always equipped with a digital blanker
D	The high power used by a spread spectrum transmitter keeps its signal from being easily overpowered

42. - E9A08

What is meant by antenna bandwidth?

Select	Answer
A	The angle between the half-power radiation points
B	Antenna length divided by the number of elements
C	The angle formed between two imaginary lines drawn through the element ends
D	The frequency range over which an antenna satisfies a performance requirement

43. - E9B03

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

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

44. - E9C04

What happens to the radiation pattern of an unterminated long wire antenna as the wire length is increased?

Select	Answer
A	The lobes become more perpendicular to the wire
B	The front-to-back ratio decreases
C	The lobes align more in the direction of the wire
D	The vertical angle increases

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

46. - E9E05

How must the driven element in a 3-element Yagi be tuned to use a hairpin matching system?

Select	Answer
A	The driven element radiation resistance must be higher than the characteristic impedance of the transmission line
B	The driven element resonance must be lower than the operating frequency
C	The driven element reactance must be inductive
D	The driven element reactance must be capacitive

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

48. - E9G02

What type of coordinate system is used in a Smith chart?

Select	Answer
A	Voltage circles and current arcs
B	Voltage lines and current chords
C	Resistance lines and reactance chords
D	Resistance circles and reactance arcs

49. - E9H10

How can the output voltage of a multiple turn receiving loop antenna be increased?

Select	Answer
A	By winding adjacent turns in opposing directions
B	By reducing the permeability of the loop shield
C	By increasing either the number of wire turns in the loop or the area of the loop structure or both
D	By increasing the number of wire turns in the loop and reducing the area of the loop structure

50. - E0A08

What does SAR measure?

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

Figure E7-1

Figure E7-3

Figure E9-1