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

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1. - E1A07

Which amateur band requires transmission on specific channels rather than on a range of frequencies?

Select	Answer
A	30 meter band
B	12 meter band
C	17 meter band
D	60 meter band

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

3. - E1C01

What is a remotely controlled station?

Select	Answer
A	A station controlled by someone other than the licensee
B	A station controlled indirectly through a control link
C	A station operating under automatic control
D	A station operated away from its regular home location

4. - E1D08

Which VHF amateur service bands have frequencies available for space stations?

Select	Answer
A	6 meters and 2 meters
B	2 meters and 1.25 meters
C	2 meters
D	6 meters, 2 meters, and 1.25 meters

5. - E1E10

What must the administering VEs do after the administration of a successful examination for an amateur operator license?

Select	Answer
A	They must submit the application document to the coordinating VEC according to the coordinating VEC instructions
B	They must collect and send the documents to the NCVEC for grading
C	They must collect and send the documents to the FCC according to instructions
D	They must collect and submit the documents to the coordinating VEC for grading

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	440 MHz - 450 MHz
C	222 MHz - 223 MHz
D	420 MHz - 430 MHz

7. - E2A07

Which of the following types of signals can be relayed through a linear transponder?

Select	Answer
A	SSB and SSTV
B	FM and CW
C	All of these choices are correct
D	PSK and Packet

8. - E2B08

Which of the following is a common method of transmitting accompanying audio with amateur fast-scan television?

Select	Answer
A	A separate VHF or UHF audio link
B	Frequency-modulated sub-carrier
C	All of these choices are correct
D	Frequency modulation of the video carrier

9. - E2C12

What might help to restore contact when DX signals become too weak to copy across an entire HF band a few hours after sunset?

Select	Answer
A	Wait 24 hours before attempting another communication on the band
B	Wait 90 minutes or so for the signal degradation to pass
C	Switch to a higher frequency HF band
D	Switch to a lower frequency HF band

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	Latitude and longitude
C	Polar coordinates
D	Time and frequency

11. - E2E01

Which type of modulation is common for data emissions below 30 MHz?

Select	Answer
A	FSK
B	Spread spectrum
C	Pulse modulation
D	DTMF tones modulating an FM signal

12. - E3A10

Which type of atmospheric structure can create a path for microwave propagation?

Select	Answer
A	Wind shear
B	Dust devil
C	The jet stream
D	Temperature inversion

13. - E3B01

What is transequatorial propagation?

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

14. - E3C13

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

Select	Answer
A	Circular
B	Vertical
C	Elliptical
D	Horizontal

15. - E4A02

Which of the following parameters would a spectrum analyzer display on the vertical and horizontal axes?

Select	Answer
A	RF amplitude and time
B	SWR and frequency
C	SWR and time
D	RF amplitude and frequency

16. - E4B01

Which of the following factors most affects the accuracy of a frequency counter?

Select	Answer
A	Decade divider accuracy
B	Temperature coefficient of the logic
C	Time base accuracy
D	Input attenuator accuracy

17. - E4C16

Which of the following is caused by missing codes in an SDR receiver's analog-to-digital converter?

Select	Answer
A	Overload
B	Loss of sensitivity
C	Excess output level
D	Distortion

18. - E4D04

Which of the following may reduce or eliminate intermodulation interference in a repeater caused by another transmitter operating in close proximity?

Select	Answer
A	A Class D final amplifier
B	A band-pass filter in the feed line between the transmitter and receiver
C	A properly terminated circulator at the output of the transmitter
D	A Class C final amplifier

19. - E4E08

What type of signal is picked up by electrical wiring near a radio antenna?

Select	Answer
A	A differential-mode signal at the AC power line frequency
B	A common-mode signal at the frequency of the radio transmitter
C	Harmonics of the AC power line frequency
D	An electrical-sparking signal

20. - E5A17

What is the result of increasing the Q of an impedance-matching circuit?

Select	Answer
A	Matching bandwidth is increased
B	It has no effect on impedance matching
C	Matching range is increased
D	Matching bandwidth is decreased

21. - E5B12

What is admittance?

Select	Answer
A	The turns ratio of a transformer
B	The inverse of impedance
C	The term for the gain of a field effect transistor
D	The unit used for Q factor

22. - E5C13

What coordinate system is often used to display the resistive, inductive, and/or capacitive reactance components of impedance?

Select	Answer
A	Faraday grid
B	Maidenhead grid
C	Rectangular coordinates
D	Elliptical coordinates

23. - E5D09

What happens to reactive power in an AC circuit that has both ideal inductors and ideal capacitors?

Select	Answer
A	It is dissipated in the formation of inductive and capacitive fields
B	It is dissipated as heat in the circuit
C	It is dissipated as kinetic energy in the circuit
D	It is repeatedly exchanged between the associated magnetic and electric fields, but is not dissipated

24. - E6A10

In Figure E6-2, what is the schematic symbol for an N-channel dual-gate MOSFET?

Select	Answer
A	6
B	2
C	4
D	5

25. - E6B06

Which of the following is a common use of a hot-carrier diode?

Select	Answer
A	As a variable capacitance in an automatic frequency control circuit
B	As a VHF/UHF mixer or detector
C	As balanced mixers in FM generation
D	As a constant voltage reference in a power supply

26. - E6C02

What happens when the level of a comparator's input signal crosses the threshold?

Select	Answer
A	The feedback loop becomes unstable
B	The comparator changes its output state
C	The comparator enters latch-up
D	The IC input can be damaged

27. - E6D07

What is the usable frequency range of inductors that use toroidal cores, assuming a correct selection of core material for the frequency being used?

Select	Answer
A	From about 100 kHz to at least 1000 GHz
B	From approximately 10 Hz to no more than 3000 kHz
C	From less than 20 Hz to approximately 300 MHz
D	From a few kHz to no more than 30 MHz

28. - E6E12

Why are high-power RF amplifier ICs and transistors sometimes mounted in ceramic packages?

Select	Answer
A	To provide a low-pass frequency response
B	High-voltage insulating ability
C	Enhanced sensitivity to light
D	Better dissipation of heat

29. - E6F07

What is a solid state relay?

Select	Answer
A	A device that uses semiconductors to implement the functions of an electromechanical relay
B	A relay using transistors to drive the relay coil
C	A passive delay line
D	A mechanical relay that latches in the on or off state each time it is pulsed

30. - E7A03

Which of the following can divide the frequency of a pulse train by 2?

Select	Answer
A	An XOR gate
B	A flip-flop
C	A multiplexer
D	An OR gate

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

32. - E7C14

Which mode is most affected by non-linear phase response in a receiver IF filter?

Select	Answer
A	Digital
B	Meteor scatter
C	Video
D	Single-Sideband voice

33. - E7D15

What is the purpose of a "step-start" circuit in a high voltage power supply?

Select	Answer
A	To provide a dual-voltage output for reduced power applications
B	To compensate for variations of the incoming line voltage
C	To allow the filter capacitors to charge gradually
D	To allow for remote control of the power supply

34. - E7E12

What is a frequency discriminator stage in a FM receiver?

Select	Answer
A	A circuit for detecting FM signals
B	A circuit for filtering two closely adjacent signals
C	An FM generator circuit
D	An automatic band-switching circuit

35. - E7F13

What is the function of taps in a digital signal processing filter?

Select	Answer
A	To reduce excess signal pressure levels
B	Provide access for debugging software
C	Provide incremental signal delays for filter algorithms
D	Select the point at which baseband signals are generated

36. - E7G03

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

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

37. - E7H07

How can an oscillator's microphonic responses be reduced?

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

38. - E8A06

What is the approximate ratio of PEP-to-average power in a typical single-sideband phone signal?

Select	Answer
A	1 to 1
B	25 to 1
C	100 to 1
D	2.5 to 1

39. - E8B07

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

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

40. - E8C07

What is the necessary bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?

Select	Answer
A	15.36 kHz
B	4.8 kHz
C	9.6 kHz
D	5.76 kHz

41. - E8D04

What is the primary effect of extremely short rise or fall time on a CW signal?

Select	Answer
A	The generation of key clicks
B	Limits data speed
C	The generation of RF harmonics
D	More difficult to copy

42. - E9A07

What is meant by antenna gain?

Select	Answer
A	The ratio of the signal in the forward direction to that in the opposite direction
B	The ratio of the radiated signal strength of an antenna in the direction of maximum radiation to that of a reference antenna
C	The final amplifier gain minus the transmission line losses
D	The ratio of the amount of power radiated by an antenna compared to the transmitter output power

43. - E9B11

What is a disadvantage of decreasing the number of wire segments in an antenna model below the guideline of 10 segments per half-wavelength?

Select	Answer
A	Ground conductivity will not be accurately modeled
B	The computed feed point impedance may be incorrect
C	The antenna will become mechanically unstable
D	The resulting design will favor radiation of harmonic energy

44. - E9C02

What is the radiation pattern of two 1/4 wavelength vertical antennas spaced 1/4 wavelength apart and fed 90 degrees out of phase?

Select	Answer
A	A figure-8 end-fire along the axis of the array
B	Cardioid
C	Omni-directional
D	A figure-8 broadside to the axis of the array

45. - E9D07

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

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

46. - E9E10

Which of these choices is an effective way to match an antenna with a 100 ohm feed point impedance to a 50 ohm coaxial cable feed line?

Select	Answer
A	Connect 1/2 wavelength shorted stub of 75 ohm cable in parallel with the 50 ohm cable where it attaches to the antenna
B	Insert a 1/2 wavelength piece of 300 ohm twin-lead in series between the antenna terminals and the 50 ohm feed cable
C	Insert a 1/4-wavelength piece of 75 ohm coaxial cable transmission line in series between the antenna terminals and the 50 ohm feed cable
D	Connect a 1/4-wavelength open stub of 300 ohm twin-lead in parallel with the coaxial feed line where it connects to the antenna

47. - E9F10

What impedance does a 1/8 wavelength transmission line present to a generator when the line is shorted at the far end?

Select	Answer
A	The same as the characteristic impedance of the line
B	A capacitive reactance
C	An inductive reactance
D	The same as the input impedance to the final generator stage

48. - E9G06

On the Smith chart shown in Figure E9-3, what is the name for the large outer circle on which the reactance arcs terminate?

Select	Answer
A	Prime axis
B	Reactance axis
C	Impedance axis
D	Polar 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. - 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 E6-2

Figure E9-3