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

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1. - E1A09

What is the first action you should take if your digital message forwarding station inadvertently forwards a communication that violates FCC rules?

Select	Answer
A	Notify the nearest FCC Field Engineer's office
B	Notify the originating station that the communication does not comply with FCC rules
C	Discontinue forwarding the communication as soon as you become aware of it
D	Discontinue forwarding all messages

2. - E1B01

Which of the following constitutes a spurious emission?

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

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 earth stations, repeater stations or model craft
C	Only beacon, repeater or space stations
D	Only auxiliary, repeater or space stations

4. - E1D07

Which amateur service HF bands have frequencies authorized for space stations?

Select	Answer
A	Only the 40 m, 20 m, 17 m, 15 m, 12 m and 10 m bands
B	Only the 40 m, 30 m, 20 m, 15 m, 12 m and 10 m bands
C	Only the 40 m, 20 m, 17 m, 15 m and 10 m bands
D	All HF bands

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	3
C	4
D	2

6. - E1F10

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

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

7. - E2A04

What is meant by the term mode as applied to an amateur radio satellite?

Select	Answer
A	Whether the satellite is in a polar or equatorial orbit
B	The satellite's uplink and downlink frequency bands
C	The satellite's orientation with respect to the Earth
D	The type of signals that can be relayed through the satellite

8. - E2B05

Which of the following is an advantage of using vestigial sideband for standard fast- scan TV transmissions?

Select	Answer
A	Vestigial sideband reduces bandwidth while allowing for simple video detector circuitry
B	The vestigial sideband contains chroma information
C	The vestigial sideband carries the audio information
D	Vestigial sideband provides high frequency emphasis to sharpen the picture

9. - E2C07

What is the Cabrillo format?

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

10. - E2D05

Which of the following techniques is normally used by low Earth orbiting digital satellites to relay messages around the world?

Select	Answer
A	Store-and-forward
B	Digipeating
C	Multi-satellite relaying
D	Node hopping

11. - E2E07

What is the typical bandwidth of a properly modulated MFSK16 signal?

Select	Answer
A	316 Hz
B	550 Hz
C	31 Hz
D	2.16 kHz

12. - E3A13

Which emission mode is best for aurora propagation?

Select	Answer
A	SSB
B	CW
C	RTTY
D	FM

13. - E3B02

What is the approximate maximum range for signals using transequatorial propagation?

Select	Answer
A	5000 miles
B	2500 miles
C	7500 miles
D	1000 miles

14. - E3C08

What does the space weather term G5 mean?

Select	Answer
A	Moderate solar wind
B	Waning sunspot numbers
C	An extreme geomagnetic storm
D	Very low solar activity

15. - E4A12

Which of the following procedures is an important precaution to follow when connecting a spectrum analyzer to a transmitter output?

Select	Answer
A	All of these choices are correct
B	Attenuate the transmitter output going to the spectrum analyzer
C	Match the antenna to the load
D	Use high quality double shielded coaxial cables to reduce signal losses

16. - E4B14

What happens if a dip meter is too tightly coupled to a tuned circuit being checked?

Select	Answer
A	Intermodulation distortion occurs
B	A less accurate reading results
C	Harmonics are generated
D	Cross modulation occurs

17. - E4C16

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

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

18. - E4D03

How can intermodulation interference between two repeaters occur?

Select	Answer
A	When the repeaters are in close proximity and the signals cause feedback in the final amplifier of one or both transmitters
B	When the signals from the transmitters are reflected out of phase from airplanes passing overhead
C	When the repeaters are in close proximity and the signals mix in the final amplifier of one or both transmitters
D	When the signals from the transmitters are reflected in phase from airplanes passing overhead

19. - E4E04

How can conducted and radiated noise caused by an automobile alternator be suppressed?

Select	Answer
A	By installing a high-pass filter in series with the radio's power lead and a low-pass filter in parallel with the field lead
B	By installing a noise suppression resistor and a blocking capacitor in both leads
C	By connecting the radio's power leads directly to the battery and by installing coaxial capacitors in line with the alternator leads
D	By installing filter capacitors in series with the DC power lead and a blocking capacitor in the field lead

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

21. - E5B04

What is the time constant of a circuit having two 220 microfarad capacitors and two 1 megohm resistors, all in parallel?

Select	Answer
A	55 seconds
B	440 seconds
C	110 seconds
D	220 seconds

22. - E5C01

Which of the following represents a capacitive reactance in rectangular notation?

Select	Answer
A	-jX
B	+jX
C	Omega
D	X

23. - E5D12

How many watts are consumed in a circuit having a power factor of 0.2 if the input is 100-VAC at 4 amperes?

Select	Answer
A	400 watts
B	2000 watts
C	50 watts
D	80 watts

24. - E6A10

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

Select	Answer
A	4
B	5
C	2
D	6

25. - E6B11

What is used to control the attenuation of RF signals by a PIN diode?

Select	Answer
A	Reverse voltage larger than the RF signal
B	Capacitance of an RF coupling capacitor
C	Forward DC bias current
D	A sub-harmonic pump signal

26. - E6C03

What is tri-state logic?

Select	Answer
A	Proprietary logic devices manufactured by Tri-State Devices
B	Logic devices that utilize ternary math
C	Logic devices with 0, 1, and high impedance output states
D	Low power logic devices designed to operate at 3 volts

27. - E6D10

What is a primary advantage of using a toroidal core instead of a solenoidal core in an inductor?

Select	Answer
A	Toroidal cores make it easier to couple the magnetic energy into other components
B	Toroidal cores have lower Q characteristics
C	Toroidal cores exhibit greater hysteresis
D	Toroidal cores confine most of the magnetic field within the core material

28. - E6E07

Which of the following is typically used to construct a MMIC-based microwave amplifier?

Select	Answer
A	Point-to-point construction
B	Ground-plane construction
C	Microstrip construction
D	Wave-soldering construction

29. - E6F14

Which of the following is true of LCD displays?

Select	Answer
A	All of these choices are correct
B	They only display alphanumeric symbols
C	They may be hard view through polarized lenses
D	They are hard to view in high ambient light conditions

30. - E7A08

What logical operation does an OR gate perform?

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

31. - E7B07

Which of the following is a likely result when a Class C amplifier is used to amplify a single-sideband phone signal?

Select	Answer
A	Increased overall intelligibility
B	Reduced intermodulation products
C	Signal distortion and excessive bandwidth
D	Signal inversion

32. - E7C07

What kind of filter would you use to attenuate an interfering carrier signal while receiving an SSB transmission?

Select	Answer
A	A notch filter
B	An all-pass filter
C	A Pi-network filter
D	A band-pass filter

33. - E7D15

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

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

34. - E7E02

What is the function of a reactance modulator?

Select	Answer
A	To produce PM signals by using an electrically variable inductance or capacitance
B	To produce AM signals by using an electrically variable inductance or capacitance
C	To produce PM signals by using an electrically variable resistance
D	To produce AM signals by using an electrically variable resistance

35. - E7F16

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

Select	Answer
A	Multiply each sample value by a factor of 3/4
B	Interpolate by a factor of three, then decimate by a factor of four
C	Change the gain 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 difference between the output voltage of the op-amp and the input voltage required in the immediately following stage
C	The output voltage of the op-amp minus its input voltage
D	The differential input voltage needed to bring the open loop output voltage to zero

37. - E7H03

How is positive feedback supplied in a Hartley oscillator?

Select	Answer
A	Through a tapped coil
B	Through link coupling
C	Through a neutralizing capacitor
D	Through a capacitive divider

38. - E8A03

What type of wave does a Fourier analysis show to be made up of sine waves of a given fundamental frequency plus all of its harmonics?

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

39. - E8B10

What describes frequency division multiplexing?

Select	Answer
A	Two or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter
B	Two or more information streams are merged into a baseband, which then modulates the transmitter
C	The transmitted signal is divided into packets of information
D	The transmitted signal jumps from band to band at a predetermined rate

40. - E8C10

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

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

41. - E8D01

Why are received spread spectrum signals resistant to interference?

Select	Answer
A	The receiver is always equipped with a digital blanker
B	If interference is detected by the receiver it will signal the transmitter to change frequencies
C	Signals not using the spread spectrum algorithm are suppressed in the receiver
D	The high power used by a spread spectrum transmitter keeps its signal from being easily overpowered

42. - E9A02

What antenna has no gain in any direction?

Select	Answer
A	Yagi
B	Isotropic antenna
C	Half-wave dipole
D	Quarter-wave vertical

43. - E9B14

What type of information can be obtained by submitting the details of a proposed new antenna to a modeling program?

Select	Answer
A	Polar plots of the far field elevation and azimuth patterns
B	Antenna gain
C	All of these choices are correct
D	SWR vs frequency charts

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	Omni-directional
C	A figure-8 broadside to the axis of the array
D	Cardioid

45. - E9D08

What happens as the Q of an antenna increases?

Select	Answer
A	SWR bandwidth increases
B	More common-mode current is present on the feed line
C	SWR bandwidth decreases
D	Gain is reduced

46. - E9E08

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

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

47. - E9F15

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

Select	Answer
A	The same as the characteristic impedance of the line
B	Very high impedance
C	Very low impedance
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	Radiation resistance
B	Radio propagation
C	Antenna radiation pattern
D	Impedance along transmission lines

49. - E9H07

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

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

50. - E0A09

Which insulating material commonly used as a thermal conductor for some types of electronic devices is extremely toxic if broken or crushed and the particles are accidentally inhaled?

Select	Answer
A	Beryllium Oxide
B	Uranium Hexafluoride
C	Mica
D	Zinc oxide

Figure E6-2