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

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1. - E1A11

Which of the following describes authorization or licensing required when operating an amateur station aboard a U.S.-registered vessel in international waters?

Select	Answer
A	Any amateur license with an FCC Marine or Aircraft endorsement
B	Any FCC-issued amateur license
C	An unrestricted Radiotelephone Operator Permit
D	Only General class or higher amateur licenses

2. - E1B07

What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?

Select	Answer
A	3.0
B	2.0
C	1.0
D	0.5

3. - E1C07

What is meant by local control?

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

4. - E1D04

What is an Earth station in the amateur satellite service?

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

5. - E1E01

What is the minimum number of qualified VEs required to administer an Element 4 amateur operator license examination?

Select	Answer
A	5
B	2
C	4
D	3

6. - E1F05

Amateur stations may not transmit in which of the following frequency segments if they are located in the contiguous 48 states and north of Line A?

Select	Answer
A	53 MHz - 54 MHz
B	420 MHz - 430 MHz
C	440 MHz - 450 MHz
D	222 MHz - 223 MHz

7. - E2A14

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

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

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. - E2C06

During a VHF/UHF contest, in which band segment would you expect to find the highest level of activity?

Select	Answer
A	At the top of each band, usually in a segment reserved for contests
B	In the weak signal segment of the band, with most of the activity near the calling frequency
C	In the middle of each band, usually on the national calling frequency
D	In the middle of the band, usually 25 kHz above the national calling frequency

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. - E2E04

What is indicated when one of the ellipses in an FSK crossed-ellipse display suddenly disappears?

Select	Answer
A	The mark and space signal have been inverted
B	The receiver has drifted 5 kHz from the desired receive frequency
C	Selective fading has occurred
D	One of the signal filters is saturated

12. - E3A07

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

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

13. - E3B04

What is meant by the terms extraordinary and ordinary waves?

Select	Answer
A	Long path and short path waves
B	Extraordinary waves describe rare long skip propagation compared to ordinary waves which travel shorter distances
C	Refracted rays and reflected waves
D	Independent waves created in the ionosphere that are elliptically polarized

14. - E3C13

What type of polarization is best for ground-wave propagation?

Select	Answer
A	Vertical
B	Horizontal
C	Circular
D	Elliptical

15. - E4A03

Which of the following test instrument is used to display spurious signals and/or intermodulation distortion products in an SSB transmitter?

Select	Answer
A	A spectrum analyzer
B	A time-domain reflectometer
C	A logic analyzer
D	A wattmeter

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	146.52 kHz
B	10 Hz
C	146.52 Hz
D	1465.20 Hz

17. - E4C14

What transmit frequency might generate an image response signal in a receiver tuned to 14.300 MHz and which uses a 455 kHz IF frequency?

Select	Answer
A	15.210 MHz
B	14.445 MHz
C	13.845 MHz
D	14.755 MHz

18. - E4D10

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

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

19. - E4E15

Which of the following can cause shielded cables to radiate or receive interference?

Select	Answer
A	Use of braided shielding material
B	Common mode currents on the shield and conductors
C	Low inductance ground connections at both ends of the shield
D	Tying all ground connections to a common point resulting in differential mode currents in the shield

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 leads the current by 90 degrees
D	The voltage and current are in phase

21. - E5B02

What is the term for the time it takes for a charged capacitor in an RC circuit to discharge to 36.8% of its initial voltage?

Select	Answer
A	One time constant
B	A discharge factor of one
C	One discharge period
D	An exponential discharge rate of one

22. - E5C03

Which of the following represents an inductive reactance in polar coordinates?

Select	Answer
A	A negative real part
B	A negative phase angle
C	A positive real part
D	A positive phase angle

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	355 W
C	1.42 mW
D	252 W

24. - E6A04

What is the name given to an impurity atom that adds holes to a semiconductor crystal structure?

Select	Answer
A	N-type impurity
B	Insulator impurity
C	Donor impurity
D	Acceptor impurity

25. - E6B08

Which of the following describes a type of semiconductor diode?

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

26. - E6C04

What is the primary advantage of tri-state logic?

Select	Answer
A	Low power consumption
B	High speed operation
C	More efficient arithmetic operations
D	Ability to connect many device outputs to a common bus

27. - E6D14

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

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

28. - E6E06

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

Select	Answer
A	Nearly infinite gain, very high input impedance, and very low output impedance
B	The ability to retrieve information from a single signal even in the presence of other strong signals
C	Controlled gain, low noise figure, and constant input and output impedance over the specified frequency range
D	Plate current that is controlled by a control grid

29. - E6F10

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

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

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

31. - E7B02

What is a Class D amplifier?

Select	Answer
A	A frequency doubling amplifier
B	A low power amplifier that uses a differential amplifier for improved linearity
C	A type of amplifier that uses switching technology to achieve high efficiency
D	An amplifier that uses drift-mode FETs for high efficiency

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	Pi
B	Omega
C	Pi-L
D	Cascode

33. - E7D02

What is one characteristic of a switching electronic voltage regulator?

Select	Answer
A	The resistance of a control element is varied in direct proportion to the line voltage or load current
B	It gives a ramp voltage at its output
C	The controlled device's duty cycle is changed to produce a constant average output voltage
D	It is generally less efficient than a linear regulator

34. - E7E07

What is meant by the term baseband in radio communications?

Select	Answer
A	The unmodulated bandwidth of the transmitted signal
B	The frequency components present in the modulating signal
C	The lowest frequency band that the transmitter or receiver covers
D	The basic oscillator frequency in an FM transmitter that is multiplied to increase the deviation and carrier frequency

35. - E7F16

How might the sampling rate of an existing digital signal be adjusted by a factor of 3/4?

Select	Answer
A	Change the gain by a factor of 3/4
B	Interpolate by a factor of three, then decimate by a factor of four
C	Multiply each sample value by a factor of 3/4
D	Add 3 to each input value and subtract 4 from each output value

36. - E7G04

What is meant by the term op-amp input offset voltage?

Select	Answer
A	The potential between the amplifier input terminals of the op-amp in an open loop condition
B	The output voltage of the op-amp minus its input voltage
C	The difference between the output voltage of the op-amp and the input voltage required in the immediately following stage
D	The differential input voltage needed to bring the open loop output voltage to zero

37. - E7H07

How can an oscillator's microphonic responses be reduced?

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

38. - E8A10

What is the purpose of a low pass filter used in conjunction with a digital-to-analog converter?

Select	Answer
A	All of these choices are correct
B	Lower the input bandwidth to increase the effective resolution
C	Improve accuracy by removing out of sequence codes from the input
D	Remove harmonics from the output caused by the discrete analog levels generated

39. - E8B07

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

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

40. - E8C10

What is an advantage of Gray code in digital communications where symbols are transmitted as multiple bits

Select	Answer
A	It facilitates error detection
B	It has more resolution than simple binary
C	It increases security
D	It has more possible states than simple binary

41. - E8D10

What are some of the differences between the Baudot digital code and ASCII?

Select	Answer
A	Baudot uses 5 data bits per character, ASCII uses 7 or 8; Baudot uses 2 characters as letters/figures shift codes, ASCII has no letters/figures shift code
B	Baudot uses 4 data bits per character, ASCII uses 7 or 8; Baudot uses 1 character as a letters/figures shift code, ASCII has no letters/figures code
C	Baudot uses 7 data bits per character, ASCII uses 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes
D	Baudot uses 6 data bits per character, ASCII uses 7 or 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes

42. - E9A03

Why would one need to know the feed point impedance of an antenna?

Select	Answer
A	To measure the near-field radiation density from a transmitting antenna
B	To calculate the front-to-back ratio of the antenna
C	To calculate the front-to-side ratio of the antenna
D	To match impedances in order to minimize standing wave ratio on the transmission line

43. - E9B12

What is the far field of an antenna?

Select	Answer
A	The region where radiated power dissipates over a specified time period
B	The region of the ionosphere where radiated power is not refracted
C	The region where radiated field strengths are obstructed by objects of reflection
D	The region where the shape of the antenna pattern is independent of distance

44. - E9C09

What is a G5RV antenna?

Select	Answer
A	A multi-band trap antenna
B	A multi-band dipole antenna fed with coax and a balun through a selected length of open wire transmission line
C	A phased array antenna consisting of multiple loops
D	A wide band dipole using shorted coaxial cable for the radiating elements and fed with a 4:1 balun

45. - E9D09

What is the function of a loading coil used as part of an HF mobile antenna?

Select	Answer
A	To increase the SWR bandwidth
B	To lower the losses
C	To lower the Q
D	To cancel capacitive reactance

46. - E9E11

What is an effective way of matching a feed line to a VHF or UHF antenna when the impedances of both the antenna and feed line are unknown?

Select	Answer
A	Use a 50 ohm 1:1 balun between the antenna and feed line
B	Use the universal stub matching technique
C	Connect a series-resonant LC network across the antenna feed terminals
D	Connect a parallel-resonant LC network across the antenna feed terminals

47. - E9F02

Which of the following determines the velocity factor of a transmission line?

Select	Answer
A	The termination impedance
B	The line length
C	The center conductor resistivity
D	Dielectric materials used in the line

48. - E9G07

On the Smith chart shown in Figure E9-3, what is the only straight line shown?

Select	Answer
A	The reactance axis
B	The resistance axis
C	The voltage axis
D	The current axis

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. - E0A10

What toxic material may be present in some electronic components such as high voltage capacitors and transformers?

Select	Answer
A	Polymorphic silicon
B	Polytetrafluroethylene
C	Polychlorinated Biphenyls
D	Polyethylene

Figure E9-3