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

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1. - E1A08

If a station in a message forwarding system inadvertently forwards a message that is in violation of FCC rules, who is primarily accountable for the rules violation?

Select	Answer
A	The control operators of all the stations in the system not authenticating the source from which they accept communications
B	The control operators of all the stations in the system
C	The control operator of the originating station
D	The control operator of the packet bulletin board station

2. - E1B01

Which of the following constitutes a spurious emission?

Select	Answer
A	Any transmitted signal that unintentionally interferes with another licensed radio station
B	A signal transmitted to prevent its detection by any station other than the intended recipient
C	An amateur station transmission made at random without the proper call sign identification
D	An emission outside its necessary bandwidth that can be reduced or eliminated without affecting the information transmitted

3. - E1C12

What types of communications may be transmitted to amateur stations in foreign countries?

Select	Answer
A	Communications incidental to the purpose of the amateur service and remarks of a personal nature
B	Business-related messages for non-profit organizations
C	All of these choices are correct
D	Messages intended for connection to users of the maritime satellite service

4. - E1D10

Which amateur stations are eligible to be telecommand stations?

Select	Answer
A	All of these choices are correct
B	Any amateur station so designated by the ITU
C	Any amateur station so designated by the space station licensee, subject to the privileges of the class of operator license held by the control operator
D	Any amateur station designated by NASA

5. - E1E05

What is the minimum passing score on amateur operator license examinations?

Select	Answer
A	Minimum passing score of 74%
B	Minimum passing score of 77%
C	Minimum passing score of 70%
D	Minimum passing score of 80%

6. - E1F04

Which of the following geographic descriptions approximately describes "Line A"?

Select	Answer
A	A line roughly parallel to and south of the U.S.-Canadian border
B	A line roughly parallel to and west of the U.S. Atlantic coastline
C	A line roughly parallel to and north of the U.S.-Mexican border and Gulf coastline
D	A line roughly parallel to and east of the U.S. Pacific coastline

7. - E2A01

What is the direction of an ascending pass for an amateur satellite?

Select	Answer
A	From west to east
B	From south to north
C	From east to west
D	From north to south

8. - E2B16

Which is a video standard used by North American Fast Scan ATV stations?

Select	Answer
A	Scottie
B	DRM
C	NTSC
D	PAL

9. - E2C01

Which of the following is true about contest operating?

Select	Answer
A	Operators are permitted to make contacts even if they do not submit a log
B	Interference to other amateurs is unavoidable and therefore acceptable
C	Every contest requires a signal report in the exchange
D	It is mandatory to transmit the call sign of the station being worked as part of every transmission to that station

10. - E2D02

Which of the following is a good technique for making meteor scatter contacts?

Select	Answer
A	Short transmission with rapidly repeated call signs and signal reports
B	All of these choices are correct
C	Use of high speed CW or digital modes
D	15 second timed transmission sequences with stations alternating based on location

11. - E2E05

Which type of digital mode does not support keyboard-to-keyboard operation?

Select	Answer
A	PSK31
B	RTTY
C	Winlink
D	MFSK

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	East
B	North
C	West
D	South

13. - E3B01

What is transequatorial propagation?

Select	Answer
A	Propagation between two mid-latitude points at approximately the same distance north and south of the magnetic equator
B	Propagation between two stations at the same latitude
C	Propagation between two continents by way of ducts along the magnetic equator
D	Propagation between any two points located on the magnetic equator

14. - E3C07

Which of the following descriptors indicates the greatest solar flare intensity?

Select	Answer
A	Class M
B	Class A
C	Class B
D	Class X

15. - E4A08

Which of the following instrument would be best for measuring the SWR of a beam antenna?

Select	Answer
A	An antenna analyzer
B	An ohmmeter
C	A Q meter
D	A spectrum analyzer

16. - E4B15

Which of the following can be used as a relative measurement of the Q for a series-tuned circuit?

Select	Answer
A	The frequency shift
B	The bandwidth of the circuit's frequency response
C	The inductance to capacitance ratio
D	The resonant frequency of the circuit

17. - E4C08

An SDR receiver is overloaded when input signals exceed what level?

Select	Answer
A	The maximum count value of the analog-to-digital converter
B	The reference voltage of the analog-to-digital converter
C	One-half the maximum sampling buffer size
D	One-half the maximum sample rate

18. - E4D14

Which of the following is a way to reduce the likelihood of receiver desensitization?

Select	Answer
A	Switch from fast AGC to slow AGC
B	Decrease the RF bandwidth of the receiver
C	Raise the receiver IF frequency
D	Increase the receiver front end gain

19. - E4E13

What might be the cause of a loud roaring or buzzing AC line interference that comes and goes at intervals?

Select	Answer
A	Arcing contacts in a thermostatically controlled device
B	All of these choices are correct
C	A malfunctioning illuminated advertising display
D	A defective doorbell or doorbell transformer inside a nearby residence

20. - E5A03

What is the magnitude of the impedance of a series RLC circuit at resonance?

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

21. - E5B11

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 25 ohms, R is 100 ohms, and XL is 50 ohms?

Select	Answer
A	14 degrees with the voltage leading the current
B	76 degrees with the voltage leading the current
C	76 degrees with the voltage lagging the current
D	14 degrees with the voltage lagging the current

22. - E5C12

If you plot the impedance of a circuit using the rectangular coordinate system and find the impedance point falls on the right side of the graph on the horizontal axis, what do you know about the circuit?

Select	Answer
A	It has to be a direct current circuit
B	It contains resistance and capacitive reactance
C	It contains resistance and inductive reactance
D	It is equivalent to a pure resistance

23. - E5D03

What is microstrip?

Select	Answer
A	Precision printed circuit conductors above a ground plane that provide constant impedance interconnects at microwave frequencies
B	Miniature coax used for low power applications
C	Lightweight transmission line made of common zip cord
D	Short lengths of coax mounted on printed circuit boards to minimize time delay between microwave circuits

24. - E6A16

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

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

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

26. - E6C13

Which of the following is an advantage of BiCMOS logic?

Select	Answer
A	Its simplicity results in much less expensive devices than standard CMOS
B	All of these choices are correct
C	It is totally immune to electrostatic damage
D	It has the high input impedance of CMOS and the low output impedance of bipolar transistors

27. - E6D06

What core material property determines the inductance of a toroidal inductor?

Select	Answer
A	Reactivity
B	Resistance
C	Permeability
D	Thermal impedance

28. - E6E05

Which of the following noise figure values is typical of a low-noise UHF preamplifier?

Select	Answer
A	2 dB
B	-10 dB
C	44 dBm
D	-20 dBm

29. - E6F02

What happens to the conductivity of a photoconductive material when light shines on it?

Select	Answer
A	It stays the same
B	It decreases
C	It becomes unstable
D	It increases

30. - E7A09

What logical operation is performed by an exclusive NOR gate?

Select	Answer
A	It produces logic "0" at its output only if all inputs are logic "0"
B	It produces logic "1" at its output only if all inputs are logic "1"
C	It produces logic "0" at its output if any single input is logic "1"
D	It produces logic "1" at its output if any single input is logic "1"

31. - E7B17

Why are odd-order rather than even-order intermodulation distortion products of concern in linear power amplifiers?

Select	Answer
A	Because they are relatively far in frequency from the desired signal
B	Because they maintain the sidebands, thus causing multiple duplicate signals
C	Because they are relatively close in frequency to the desired signal
D	Because they invert the sidebands causing distortion

32. - E7C15

What is a crystal lattice filter?

Select	Answer
A	A filter with narrow bandwidth and steep skirts made using quartz crystals
B	A power supply filter made with interlaced quartz crystals
C	An audio filter made with four quartz crystals that resonate at 1kHz intervals
D	A filter with wide bandwidth and shallow skirts made using quartz crystals

33. - E7D08

What type of circuit is shown in Figure E7-3?

Select	Answer
A	Emitter follower
B	Switching voltage regulator
C	Grounded emitter amplifier
D	Linear voltage regulator

34. - E7E05

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

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

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	10 bits
B	8 bits
C	6 bits
D	4 bits

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. - E7H09

What type of frequency synthesizer circuit uses a phase accumulator, lookup table, digital to analog converter, and a low-pass anti-alias filter?

Select	Answer
A	A diode-switching matrix synthesizer
B	A hybrid synthesizer
C	A direct digital synthesizer
D	A phase locked loop synthesizer

38. - E8A02

What type of wave has a rise time significantly faster than its fall time (or vice versa)?

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

39. - E8B05

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus-or-minus 5 kHz when the maximum modulation frequency is 3 kHz?

Select	Answer
A	0.167
B	0.6
C	60
D	1.67

40. - E8C06

What is the necessary bandwidth of a 170-hertz shift, 300-baud ASCII transmission?

Select	Answer
A	0.3 kHz
B	0.1 Hz
C	0.5 kHz
D	1.0 kHz

41. - E8D10

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

Select	Answer
A	Baudot uses 7 data bits per character, ASCII uses 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes
B	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
C	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
D	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

42. - E9A03

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

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

43. - E9B04

What may occur when a directional antenna is operated at different frequencies within the band for which it was designed?

Select	Answer
A	The E-field and H-field patterns may reverse
B	The gain may change depending on frequency
C	Element spacing limits could be exceeded
D	Feed point impedance may become negative

44. - E9C10

Which of the following describes a Zepp antenna?

Select	Answer
A	A vertical array capable of quickly changing the direction of maximum radiation by changing phasing lines
B	An omni-directional antenna commonly used for satellite communications
C	A dipole constructed from zip cord
D	An end fed dipole antenna

45. - E9D11

Which of the following types of conductors would be best for minimizing losses in a station's RF ground system?

Select	Answer
A	A resistive wire, such as spark plug wire
B	A single 12 gauge or 10 gauge stainless steel wire
C	A cable with six or seven 18 gauge conductors in parallel
D	A wide flat copper strap

46. - E9E02

What is the name of an antenna matching system that matches an unbalanced feed line to an antenna by feeding the driven element both at the center of the element and at a fraction of a wavelength to one side of center?

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

47. - E9F14

What impedance does a 1/2 wavelength transmission line present to a generator when the line is shorted at the far end?

Select	Answer
A	Very high impedance
B	Very low impedance
C	The same as the characteristic impedance of the line
D	The same as the output impedance of the generator

48. - E9G01

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

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

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 increasing the number of wire turns in the loop and reducing the area of the loop structure
C	By reducing the permeability of the loop shield
D	By increasing either the number of wire turns in the loop or the area of the loop structure or both

50. - E0A10

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

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

Figure E7-3

Figure E7-4