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

2. - E1B08

What limitations may the FCC place on an amateur station if its signal causes interference to domestic broadcast reception, assuming that the receivers involved are of good engineering design?

Select	Answer
A	The amateur station must cease operation on all frequencies above 30 MHz
B	The amateur station must avoid transmitting during certain hours on frequencies that cause the interference
C	The amateur station must cease operation
D	The amateur station must cease operation on all frequencies below 30 MHz

3. - E1C10

What types of amateur stations may automatically retransmit the radio signals of other amateur stations?

Select	Answer
A	Only auxiliary, beacon or space stations
B	Only auxiliary, repeater or space stations
C	Only beacon, repeater or space stations
D	Only earth stations, repeater stations or model craft

4. - E1D03

What is a telecommand station in the amateur satellite service?

Select	Answer
A	An amateur station located on the Earth's surface for communication with other Earth stations by means of Earth satellites
B	An amateur station that transmits communications to initiate, modify or terminate functions of a space station
C	An amateur station located more than 50 km above the Earth's surface
D	An amateur station that transmits telemetry consisting of measurements of upper atmosphere

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 VEC coordinating the session
C	Each administering VE
D	The VE session manager

6. - E1F10

What is the maximum permitted transmitter peak envelope power for an amateur station transmitting spread spectrum communications?

Select	Answer
A	1.5 kW
B	1.5 W
C	1 W
D	10 W

7. - E2A13

What type of satellite appears to stay in one position in the sky?

Select	Answer
A	LEO
B	HEO
C	Geostationary
D	Geomagnetic

8. - E2B03

How is an interlaced scanning pattern generated in a fast-scan (NTSC) television system?

Select	Answer
A	By scanning lines from left to right in one field and right to left in the next
B	By scanning each field from bottom to top
C	By scanning odd numbered lines in one field and even numbered lines in the next
D	By scanning two fields simultaneously

9. - E2C05

What is the function of a DX QSL Manager?

Select	Answer
A	To allocate frequencies for DXpeditions
B	To relay calls to and from a DX station
C	To handle the receiving and sending of confirmation cards for a DX station
D	To run a net to allow many stations to contact a rare DX station

10. - E2D14

What is one advantage of using JT65 coding?

Select	Answer
A	Permits fast-scan TV transmissions over narrow bandwidth
B	The ability to decode signals which have a very low signal to noise ratio
C	Easily copied by ear if necessary
D	Uses only a 65 Hz bandwidth

11. - E2E13

Which of the following is a possible reason that attempts to initiate contact with a digital station on a clear frequency are unsuccessful?

Select	Answer
A	All of these choices are correct
B	Your transmit frequency is incorrect
C	The protocol version you are using is not the supported by the digital station
D	Another station you are unable to hear is using the frequency

12. - E3A04

What do Hepburn maps predict?

Select	Answer
A	Probability of tropospheric propagation
B	Locations of auroral reflecting zones
C	Likelihood of rain-scatter along cold or warm fronts
D	Sporadic E propagation

13. - E3B14

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

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

14. - E3C13

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

Select	Answer
A	Vertical
B	Circular
C	Horizontal
D	Elliptical

15. - E4A15

What is an advantage of a period-measuring frequency counter over a direct-count type?

Select	Answer
A	It can run on battery power for remote measurements
B	It can directly measure the modulation index of an FM transmitter
C	It does not require an expensive high-precision time base
D	It provides improved resolution of low-frequency signals within a comparable time period

16. - E4B13

Which S parameter is equivalent to forward gain?

Select	Answer
A	S12
B	S22
C	S21
D	S11

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

18. - E4D01

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

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

19. - E4E09

What undesirable effect can occur when using an IF noise blanker?

Select	Answer
A	The audio frequency bandwidth of the received signal might be compressed
B	FM signals can no longer be demodulated
C	Nearby signals may appear to be excessively wide even if they meet emission standards
D	Received audio in the speech range might have an echo effect

20. - E5A14

What is the resonant frequency of a series RLC circuit if R is 22 ohms, L is 50 microhenrys and C is 40 picofarads?

Select	Answer
A	1.78 MHz
B	22.36 MHz
C	3.56 MHz
D	44.72 MHz

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	Current leads voltage by 90 degrees
C	Voltage leads current by 90 degrees
D	Voltage and current are in phase

22. - E5C09

When using rectangular coordinates to graph the impedance of a circuit, what does the horizontal axis represent?

Select	Answer
A	The difference between the resistive and reactive components
B	The sum of the reactive and resistive components
C	Reactive component
D	Resistive component

23. - E5D03

What is microstrip?

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

24. - E6A07

Which of the following indicates that a silicon NPN junction transistor is biased on?

Select	Answer
A	Base-to-emitter voltage of approximately 6 to 7 volts
B	Base-to-emitter voltage of approximately 0.6 to 0.7 volts
C	Base-to-emitter resistance of approximately 0.6 to 0.7 ohms
D	Base-to-emitter resistance of approximately 6 to 7 ohms

25. - E6B07

What is the failure mechanism when a junction diode fails due to excessive current?

Select	Answer
A	Insufficient forward voltage
B	Excessive inverse voltage
C	Charge carrier depletion
D	Excessive junction temperature

26. - E6C01

What is the function of hysteresis in a comparator?

Select	Answer
A	To allow the comparator to be used with AC input signal
B	To prevent input noise from causing unstable output signals
C	To increase the sensitivity
D	To cause the output to change states continually

27. - E6D14

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

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

28. - E6E10

What is the packaging technique in which leadless components are soldered directly to circuit boards?

Select	Answer
A	Stripped lead
B	Virtual lead mounting
C	Direct soldering
D	Surface mount

29. - E6F13

What is a liquid crystal display (LCD)?

Select	Answer
A	A modern replacement for a quartz crystal oscillator which displays its fundamental frequency
B	A display utilizing a crystalline liquid and polarizing filters which becomes opaque when voltage is applied
C	A display that uses a glowing liquid to remain brightly lit in dim light
D	A frequency-determining unit for a transmitter or receiver

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

31. - E7B16

What is the effect of intermodulation products in a linear power amplifier?

Select	Answer
A	All of these choices are correct
B	Transmission of spurious signals
C	Low efficiency
D	Creation of parasitic oscillations

32. - E7C13

What is one advantage of a Pi-matching network over an L-matching network consisting of a single inductor and a single capacitor?

Select	Answer
A	L-networks cannot perform impedance transformation
B	The Q of Pi-networks can be varied depending on the component values chosen
C	Pi-networks have fewer components
D	Pi-networks are designed for balanced input and output

33. - E7D10

What is the primary reason that a high-frequency switching type high voltage power supply can be both less expensive and lighter in weight than a conventional power supply?

Select	Answer
A	It uses a diode bridge rectifier for increased output
B	The high frequency inverter design uses much smaller transformers and filter components for an equivalent power output
C	The inverter design does not require any output filtering
D	It uses a large power factor compensation capacitor to create free power from the unused portion of the AC cycle

34. - E7E09

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

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

35. - E7F08

What is the function of decimation with regard to digital filters?

Select	Answer
A	Attenuating the signal
B	Reducing the effective sample rate by removing samples
C	Converting data to binary code decimal form
D	Removing unnecessary significant digits

36. - E7G10

What absolute voltage gain can be expected from the circuit in Figure E7-4 when R1 is 1800 ohms and RF is 68 kilohms?

Select	Answer
A	38
B	76
C	0.03
D	1

37. - E7H11

What are the major spectral impurity components of direct digital synthesizers?

Select	Answer
A	Broadband noise
B	Digital conversion noise
C	Nyquist limit noise
D	Spurious signals at discrete frequencies

38. - E8A05

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

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

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	0.6
B	60
C	0.167
D	1.67

40. - E8C09

Which is the name of a digital code where each preceding or following character changes by only one bit?

Select	Answer
A	Excess 3 code
B	Gray code
C	Extended Binary Coded Decimal Interchange Code
D	Binary Coded Decimal Code

41. - E8D12

What is the advantage of including a parity bit with an ASCII character stream?

Select	Answer
A	Foreign language characters can be sent
B	Some types of errors can be detected SUBELEMENT E9 - ANTENNAS AND TRANSMISSION LINES [8 Exam Questions - 8 Groups] E9A Basic Antenna parameters: radiation resistance, gain, beamwidth, efficiency, beamwidth; effective radiated power, polarization E9A01 (C) What describes an isotropic antenna? A. A grounded antenna used to measure earth conductivity B. A horizontally polarized antenna used to compare Yagi antennas C. A theoretical antenna used as a reference for antenna gain D. A spacecraft antenna used to direct signals toward the earth
C	The signal can overpower interfering signals
D	Faster transmission rate

42. - E9A13

How much gain does an antenna have compared to a 1/2-wavelength dipole when it has 12 dB gain over an isotropic antenna?

Select	Answer
A	6.17 dB
B	12.5 dB
C	9.85 dB
D	14.15 dB

43. - E9B01

In the antenna radiation pattern shown in Figure E9-1, what is the 3 dB beam-width?

Select	Answer
A	25 degrees
B	30 degrees
C	75 degrees
D	50 degrees

44. - E9C06

What is the effect of a terminating resistor on a rhombic antenna?

Select	Answer
A	It decreases the ground loss
B	It changes the radiation pattern from bidirectional to unidirectional
C	It reflects the standing waves on the antenna elements back to the transmitter
D	It changes the radiation pattern from horizontal to vertical polarization

45. - E9D06

What happens to the bandwidth of an antenna as it is shortened through the use of loading coils?

Select	Answer
A	It is decreased
B	It becomes flat
C	It is increased
D	No change occurs

46. - E9E08

Which of the following measurements is characteristic of a mismatched transmission line?

Select	Answer
A	An SWR less than 1:1
B	A dielectric constant greater than 1
C	A reflection coefficient greater than 1
D	An SWR greater than 1:1

47. - E9F05

What is the approximate physical length of a solid polyethylene dielectric coaxial transmission line that is electrically one-quarter wavelength long at 14.1 MHz?

Select	Answer
A	3.5 meters
B	0.2 meters
C	20 meters
D	2.3 meters

48. - E9G11

How are the wavelength scales on a Smith chart calibrated?

Select	Answer
A	In fractions of transmission line electrical frequency
B	In fractions of antenna electrical wavelength
C	In fractions of antenna electrical frequency
D	In fractions of transmission line electrical wavelength

49. - E9H07

Why is it advisable to use an RF attenuator on a receiver being used for direction finding?

Select	Answer
A	It prevents receiver overload which could make it difficult to determine peaks or nulls
B	It compensates for the effects of an isotropic antenna, thereby improving directivity
C	It narrows the bandwidth of the received signal to improve signal to noise ratio
D	It reduces loss of received signals caused by antenna pattern nulls, thereby increasing sensitivity

50. - E0A03

Which of the following would be a practical way to estimate whether the RF fields produced by an amateur radio station are within permissible MPE limits?

Select	Answer
A	Use a calibrated antenna analyzer
B	All of the choices are correct
C	Use a hand calculator plus Smith-chart equations to calculate the fields
D	Use an antenna modeling program to calculate field strength at accessible locations

Figure E7-4

Figure E9-1