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

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 73 dB below
B	At least 63 dB below
C	At least 43 dB below
D	At least 53 dB below

3. - E1C02

What is meant by automatic control of a station?

Select	Answer
A	The use of devices and procedures for control so that the control operator does not have to be present at a control point
B	The use of a control link between a control point and a locally controlled station
C	A station operating with its output power controlled automatically
D	Remotely controlling a station's antenna pattern through a directional control link

4. - E1D04

What is an Earth station in the amateur satellite service?

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

5. - E1E09

What may be the penalty for a VE who fraudulently administers or certifies an examination?

Select	Answer
A	All of these choices are correct
B	Revocation of the VE's amateur station license grant and the suspension of the VE's amateur operator license grant
C	A sentence of up to one year in prison
D	A fine of up to $1000 per occurrence

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. - E2A14

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

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

8. - E2B06

What is vestigial sideband modulation?

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

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. - E2D12

How does JT65 improve EME communications?

Select	Answer
A	It can decode signals many dB below the noise floor using FEC
B	It controls the receiver to track Doppler shift
C	It supplies signals to guide the antenna to track the Moon
D	All of these choices are correct

11. - E2E10

Which of these digital modes has the narrowest bandwidth?

Select	Answer
A	300-baud packet
B	170 Hz shift, 45 baud RTTY
C	PSK31
D	MFSK16

12. - E3A07

Atmospheric ducts capable of propagating microwave signals often form over what geographic feature?

Select	Answer
A	Mountain ranges
B	Urban areas
C	Forests
D	Bodies of water

13. - E3B09

At what time of year is Sporadic E propagation most likely to occur?

Select	Answer
A	Around the equinoxes, especially the spring equinox
B	Around the solstices, especially the winter solstice
C	Around the solstices, especially the summer solstice
D	Around the equinoxes, especially the fall equinox

14. - E3C14

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

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

15. - E4A10

Which of the following displays multiple digital signal states simultaneously?

Select	Answer
A	Network analyzer
B	Logic analyzer
C	Bit error rate tester
D	Modulation monitor

16. - E4B08

Which of the following is a characteristic of a good DC voltmeter?

Select	Answer
A	Low reluctance input
B	Low impedance input
C	High reluctance input
D	High impedance input

17. - E4C02

Which of the following portions of a receiver can be effective in eliminating image signal interference?

Select	Answer
A	A notch filter
B	A properly adjusted product detector
C	A narrow IF filter
D	A front-end filter or pre-selector

18. - E4D10

What does a third-order intercept level of 40 dBm mean with respect to receiver performance?

Select	Answer
A	The receiver can tolerate signals up to 40 dB above the noise floor without producing third-order intermodulation products
B	A pair of 1 mW input signals will produce a third-order intermodulation product which is 40 dB stronger than the input signal
C	Signals less than 40 dBm will not generate audible third-order intermodulation products
D	A pair of 40 dBm signals will theoretically generate a third-order intermodulation product with the same level as the input signals

19. - E4E01

Which of the following types of receiver noise can often be reduced by use of a receiver noise blanker?

Select	Answer
A	Broadband white noise
B	Heterodyne interference
C	All of these choices are correct
D	Ignition noise

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

21. - E5B04

What is the time constant of a circuit having two 220 microfarad capacitors and two 1 megohm resistors, all in parallel?

Select	Answer
A	55 seconds
B	440 seconds
C	220 seconds
D	110 seconds

22. - E5C06

What does the impedance 50-j25 represent?

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

23. - E5D17

How many watts are consumed in a circuit having a power factor of 0.6 if the input is 200VAC at 5 amperes?

Select	Answer
A	1000 watts
B	1600 watts
C	600 watts
D	200 watts

24. - E6A05

What is the alpha of a bipolar junction transistor?

Select	Answer
A	The change of collector current with respect to emitter current
B	The change of collector current with respect to base current
C	The change of collector current with respect to gate current
D	The change of base current with respect to collector current

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

26. - E6C05

What is an advantage of CMOS logic devices over TTL devices?

Select	Answer
A	Lower power consumption
B	Differential output capability
C	Immune to damage from static discharge
D	Lower distortion

27. - E6D03

Which of the following is an aspect of the piezoelectric effect?

Select	Answer
A	Mechanical deformation of material by the application of a magnetic field
B	Increased conductivity in the presence of light
C	Mechanical deformation of material by the application of a voltage
D	Generation of electrical energy in the presence of light

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	It is a CMOS analog-to-digital converter
C	It is used in a battery charger circuit
D	Its phase shift changes rapidly with frequency

29. - E6F05

Which describes an optical shaft encoder?

Select	Answer
A	A device which detects rotation of a control by interrupting a light source with a patterned wheel
B	A device which measures the strength of a beam of light using analog to digital conversion
C	A digital encryption device often used to encrypt spacecraft control signals
D	A device for generating RTTY signals by means of a rotating light source

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 stores one bit of data in either a 0 or 1 state
C	It maintains a constant output voltage, regardless of variations in the input voltage
D	It switches momentarily to the opposite binary state and then returns to its original state after a set time

31. - E7B10

In Figure E7-1, what is the purpose of R1 and R2?

Select	Answer
A	Self bias
B	Feedback
C	Fixed bias
D	Load resistors

32. - E7C12

Which describes a Pi-L-network used for matching a vacuum tube final amplifier to a 50 ohm unbalanced output?

Select	Answer
A	A Phase Inverter Load network
B	A matching network in which all components are isolated from ground
C	A network with only three discrete parts
D	A Pi-network with an additional series inductor on the output

33. - E7D14

What is one purpose of a "bleeder" resistor in a conventional unregulated power supply?

Select	Answer
A	To cut down on waste heat generated by the power supply
B	To balance the low-voltage filament windings
C	To improve output voltage regulation
D	To boost the amount of output current

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 a microphone preamplifier to produce AM signals
D	By varying the tuning of an amplifier tank circuit to produce PM signals

35. - E7F06

What is the minimum number of bits required for an analog-to-digital converter to sample a signal with a range of 1 volt at a resolution of 1 millivolt?

Select	Answer
A	6 bits
B	4 bits
C	10 bits
D	8 bits

36. - E7G07

What magnitude of voltage gain can be expected from the circuit in Figure E7-4 when R1 is 10 ohms and RF is 470 ohms?

Select	Answer
A	47
B	94
C	0.21
D	24

37. - E7H10

What information is contained in the lookup table of a direct digital frequency synthesizer?

Select	Answer
A	The amplitude values that represent a sine-wave output
B	The phase relationship between a reference oscillator and the output waveform
C	The synthesizer frequency limits and frequency values stored in the radio memories
D	The phase relationship between a voltage-controlled oscillator and the output waveform

38. - E8A05

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

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

39. - E8B09

What is meant by deviation ratio?

Select	Answer
A	The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency
B	The ratio of the carrier center frequency to the audio modulating frequency
C	The ratio of the highest audio modulating frequency to the average audio modulating frequency
D	The ratio of the audio modulating frequency to the center carrier frequency

40. - E8C05

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

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

41. - E8D08

What parameter might indicate that excessively high input levels are causing distortion in an AFSK signal?

Select	Answer
A	Repeat Request Rate (RRR)
B	Signal to noise ratio
C	Intermodulation Distortion (IMD)
D	Baud rate

42. - E9A10

Which of the following choices is a way to improve the efficiency of a ground-mounted quarter-wave vertical antenna?

Select	Answer
A	Install a good radial system
B	Isolate the coax shield from ground
C	Shorten the radiating element
D	Reduce the diameter of the radiating element

43. - E9B03

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

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

44. - E9C13

What is the main effect of placing a vertical antenna over an imperfect ground?

Select	Answer
A	It reduces losses in the radiating portion of the antenna
B	It reduces low-angle radiation
C	It changes the impedance angle of the matching network
D	It causes increased SWR

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. - E9E03

What is the name of the matching system that uses a section of transmission line connected in parallel with the feed line at or near the feed point?

Select	Answer
A	The stub match
B	The omega match
C	The delta match
D	The gamma match

47. - E9F01

What is the velocity factor of a transmission line?

Select	Answer
A	The velocity of the wave in the transmission line multiplied by the velocity of light in a vacuum
B	The ratio of the characteristic impedance of the line to the terminating impedance
C	The index of shielding for coaxial cable
D	The velocity of the wave in the transmission line divided by the velocity of light in a vacuum

48. - E9G09

What third family of circles is often added to a Smith chart during the process of solving problems?

Select	Answer
A	Radiation-pattern circles
B	Antenna-length circles
C	Coaxial-length circles
D	Standing wave ratio circles

49. - E9H08

What is the function of a sense antenna?

Select	Answer
A	It increases the sensitivity of a DF antenna array
B	It modifies the pattern of a DF antenna array to provide a null in one direction
C	It allows DF antennas to receive signals at different vertical angles
D	It provides diversity reception that cancels multipath signals

50. - E0A08

What does SAR measure?

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

Figure E7-1

Figure E7-4

Figure E9-1