78.  Dielectric strength of a medium
A. increases with the increase in temperature.
B. decreases with the increase in thickness
C. increases with moisture content
D. is not affected by the moisture content.

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79.  The time constant of an RC series circuit connected to a dc source is equal to
A. ?R
B. ?C
C. CR
D. CR

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80.  The magnetic susceptibility of a paramag-netic material is
A. less than zero.
B. less than one but positive
C. greater than one
D. equal to zero.

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81.  A keeper is used for
A. restoring of lost flux.
B. amplification of flux.
C. providing a closed path for the magnetic flux.
D. changing the direction of magnetic lines of force.

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82.  Force experienced by a unit north pole at any point is known as
A. mmf.
B. magnetic flux strength
C. magnetic flux density.
D. magnetic potential

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83.  Lines of force
A. never intersect.
B. often intersect.
C. intersect only in special circumstances.
D. are unpredictable.

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84.  Magnetostriction in a phenomenon whereby the magnetisation of a ferromagnetic material leads to a change in
A. relative permeability
B.
C.(b) physical dimensions
D.(c) spontaneous magnetization

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