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

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1. - E1A04

With your transceiver displaying the carrier frequency of phone signals, you hear a DX station calling CQ on 3.601 MHz LSB. Is it legal to return the call using lower sideband on the same frequency?

Select	Answer
A	Yes, because the displayed frequency is within the 75 meter phone band segment
B	No, the sideband will extend beyond the edge of the phone band segment
C	Yes, because the DX station initiated the contact
D	No, U.S. stations are not permitted to use phone emissions below 3.610 MHz

2. - E1B10

What frequencies are authorized to an amateur station operating under RACES rules?

Select	Answer
A	Specific local government channels
B	Military Auxiliary Radio System (MARS) channels
C	All amateur service frequencies authorized to the control operator
D	Specific segments in the amateur service MF, HF, VHF and UHF bands

3. - E1C07

What is meant by local control?

Select	Answer
A	Direct manipulation of the transmitter by a control operator
B	Controlling a station through a local auxiliary link
C	Automatically manipulating local station controls
D	Controlling a repeater using a portable handheld transceiver

4. - E1D01

What is the definition of the term telemetry?

Select	Answer
A	One-way transmission of measurements at a distance from the measuring instrument
B	One-way transmission that initiates, modifies, or terminates the functions of a device at a distance
C	Two-way single channel transmissions of data
D	Two-way radiotelephone transmissions in excess of 1000 feet

5. - E1E14

For which types of out-of-pocket expenses do the Part 97 rules state that VEs and VECs may be reimbursed?

Select	Answer
A	Preparing, processing, administering and coordinating an examination for an amateur radio license
B	Providing amateur operator license examination preparation training materials
C	No expenses are authorized for reimbursement
D	Teaching an amateur operator license examination preparation course

6. - E1F01

On what frequencies are spread spectrum transmissions permitted?

Select	Answer
A	Only on amateur frequencies above 50 MHz
B	Only on amateur frequencies above 420 MHz
C	Only on amateur frequencies above 222 MHz
D	Only on amateur frequencies above 144 MHz

7. - E2A03

What is the orbital period of an Earth satellite?

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

8. - E2B02

How many horizontal lines make up a fast-scan (NTSC) television frame?

Select	Answer
A	30
B	525
C	60
D	1080

9. - E2C07

What is the Cabrillo format?

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

10. - E2D11

Which of the following data are used by the APRS network to communicate your location?

Select	Answer
A	Radio direction finding spectrum analysis
B	Polar coordinates
C	Latitude and longitude
D	Time and frequency

11. - E2E12

Which type of control is used by stations using the Automatic Link Enable (ALE) protocol?

Select	Answer
A	Remote
B	Local
C	ALE can use any type of control
D	Automatic

12. - E3A09

Which of the following frequency range is most suited for meteor scatter communications?

Select	Answer
A	28 MHz - 148 MHz
B	220 MHz - 450 MHz
C	10 MHz - 14 MHz
D	1.8 MHz - 1.9 MHz

13. - E3B14

What happens to linearly polarized radio waves that split into ordinary and extraordinary waves in the ionosphere?

Select	Answer
A	They are bent toward the magnetic poles
B	Their polarization is randomly modified
C	They become phase-locked
D	They become elliptically polarized

14. - E3C15

What might a sudden rise in radio background noise indicate?

Select	Answer
A	A solar flare has occurred
B	A meteor ping
C	Long-path propagation is occurring
D	Increased transequatorial propagation likely

15. - E4A11

Which of the following is good practice when using an oscilloscope probe?

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

16. - E4B16

Which S parameter represents return loss or SWR?

Select	Answer
A	S11
B	S12
C	S21
D	S22

17. - E4C09

Which of the following choices is a good reason for selecting a high frequency for the design of the IF in a conventional HF or VHF communications receiver?

Select	Answer
A	Fewer components in the receiver
B	Improved receiver noise figure
C	Reduced drift
D	Easier for front-end circuitry to eliminate image responses

18. - E4D01

What is meant by the blocking dynamic range of a receiver?

Select	Answer
A	The difference in dB between the noise floor and the level of an incoming signal which will cause 1 dB of gain compression
B	The minimum difference in dB between two signals which produce third order intermodulation products greater than the noise floor
C	The difference in dB between the noise floor and the third order intercept point
D	The minimum difference in dB between the levels of two FM signals which will cause one signal to block the other

19. - E4E01

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

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

20. - E5A04

What is the magnitude of the impedance of a circuit with a resistor, an inductor and a capacitor all in parallel, at resonance?

Select	Answer
A	Approximately equal to inductive reactance
B	Approximately equal to circuit resistance
C	Approximately equal to capacitive reactance
D	Low, as compared to the circuit resistance

21. - E5B06

What is susceptance?

Select	Answer
A	The inverse of reactance
B	The magnetic impedance of a circuit
C	A measure of the efficiency of a transformer
D	The ratio of magnetic field to electric field

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 7
B	Point 3
C	Point 1
D	Point 8

23. - E5D18

How many watts are consumed in a circuit having a power factor of 0.71 if the apparent power is 500VA?

Select	Answer
A	704 W
B	1.42 mW
C	355 W
D	252 W

24. - E6A16

What are the majority charge carriers in N-type semiconductor material?

Select	Answer
A	Free protons
B	Free neutrons
C	Free electrons
D	Holes

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

26. - E6C06

Why do CMOS digital integrated circuits have high immunity to noise on the input signal or power supply?

Select	Answer
A	Input signals are stronger
B	The input switching threshold is about one-half the power supply voltage
C	The input switching threshold is about two times the power supply voltage
D	Larger bypass capacitors are used in CMOS circuit design

27. - E6D08

What is one reason for using powdered-iron cores rather than ferrite cores in an inductor?

Select	Answer
A	Powdered-iron cores use smaller diameter wire for the same inductance
B	Powdered-iron cores generally require fewer turns to produce a given inductance
C	Powdered-iron cores generally have greater initial permeability
D	Powdered-iron cores generally maintain their characteristics at higher currents

28. - E6E02

Which of the following device packages is a through-hole type?

Select	Answer
A	DIP
B	PLCC
C	Ball grid array
D	SOT

29. - E6F03

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

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

30. - E7A10

What is a truth table?

Select	Answer
A	A table of logic symbols that indicate the high logic states of an op-amp
B	A diagram showing logic states when the digital device output is true
C	A table of logic symbols that indicate the logic states of an op-amp
D	A list of inputs and corresponding outputs for a digital device

31. - E7B10

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

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

32. - E7C01

How are the capacitors and inductors of a low-pass filter Pi-network arranged between the network's input and output?

Select	Answer
A	An inductor is connected between the input and ground, another inductor is connected between the output and ground, and a capacitor is connected between the input and output
B	A capacitor is connected between the input and ground, another capacitor is connected between the output and ground, and an inductor is connected between input and output
C	Two inductors are in series between the input and output, and a capacitor is connected between the two inductors and ground
D	Two capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground

33. - E7D13

What is the equation for calculating power dissipation by a series connected linear voltage regulator?

Select	Answer
A	Voltage difference from input to output multiplied by output current
B	Input voltage multiplied by input current
C	Output voltage multiplied by output current
D	Input voltage divided by output current

34. - E7E09

What occurs when an excessive amount of signal energy reaches a mixer circuit?

Select	Answer
A	Mixer blanking occurs
B	A beat frequency is generated
C	Spurious mixer products are generated
D	Automatic limiting occurs

35. - E7F07

What function can a Fast Fourier Transform perform?

Select	Answer
A	Converting analog signals to digital form
B	Converting digital signals to analog form
C	Converting digital signals from the time domain to the frequency domain
D	Converting 8-bit data to 16 bit data

36. - E7G01

What is the typical output impedance of an integrated circuit op-amp?

Select	Answer
A	Very low
B	Very high
C	1000 ohms
D	100 ohms

37. - E7H10

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

Select	Answer
A	The synthesizer frequency limits and frequency values stored in the radio memories
B	The phase relationship between a voltage-controlled oscillator and the output waveform
C	The amplitude values that represent a sine-wave output
D	The phase relationship between a reference 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 voltage with a D'Arsonval meter
B	By measuring the heating effect in a known resistor
C	By using a grid dip meter
D	By using an absorption wave meter

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

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

41. - E8D11

What is one advantage of using ASCII code for data communications?

Select	Answer
A	It uses one character as a shift code to send numeric and special characters
B	It contains fewer information bits per character than any other code
C	It includes built in error correction features
D	It is possible to transmit both upper and lower case text

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	Shorten the radiating element
C	Isolate the coax shield from ground
D	Reduce the diameter of the radiating element

43. - E9B15

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

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

44. - E9C08

What is a folded dipole antenna?

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

45. - E9D07

What is an advantage of using top loading in a shortened HF vertical antenna?

Select	Answer
A	Higher losses
B	Greater structural strength
C	Improved radiation efficiency
D	Lower Q

46. - E9E01

What system matches a higher impedance transmission line to a lower impedance antenna by connecting the line to the driven element in two places spaced a fraction of a wavelength each side of element center?

Select	Answer
A	The omega matching system
B	The delta matching system
C	The stub matching system
D	The gamma matching system

47. - E9F04

What is the typical velocity factor for a coaxial cable with solid polyethylene dielectric?

Select	Answer
A	0.10
B	0.30
C	2.70
D	0.66

48. - E9G09

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

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

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 should be configured as a four-sided loop
C	It must be mounted more than 1 wavelength above ground
D	Its overall length must not exceed 1/4 wavelength

50. - E0A07

How may dangerous levels of carbon monoxide from an emergency generator be detected?

Select	Answer
A	By the odor
B	By the yellowish appearance of the gas
C	Only with a carbon monoxide detector
D	Any ordinary smoke detector can be used

Figure E5-2

Figure E7-1

Figure E9-2