64.  The advantage of electrostatic instruments is that
A. they are cheap, robust and small in size
B. their indicating scale is uniform
C. their operating forces are large
D. their power drain from the mains is negligible

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65.  The damping of ballistic galvanometer is kept very small
A. to make the system oscillating
B. in order to get large first deflection
C. in order to get small first deflection
D. to make the system critically damped

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66.  Electrostatic instruments are not free from effect of
A. temperature
B. frequency
C. stray magnetic field
D. stray electrostatic field

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67.  If the current sensitivity of a galvanometer is increased, the voltage sensitivity
A. decreases
B. increases
C. remains unlatered
D. may increases or decrease

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68.  For capacitance measurement, a ballistic galvanometer should have
A. a high critical resistance and a low period of oscillation
B. a high critical resistance and a high period of oscillation
C. a low critical resistance and a high period of oscillation
D. a low critical resistance and a low period of oscillation

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69.  Electrostatic voltmeters
A. are not frequency limited
B. have uniform scale
C. have scale reading rms value on ac circuits
D. have scale reading peak value on ac circuits

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70.  The fixed coil in an electrodynamometer is normally used as a
A. potential coil
B. current coil
C. either as potential coil or as current coil
D. there is no fixed coil in electrodynamometer

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