Assertion : The sensitivity of a moving coil galvanometer is incr… - Vidyadip

MCQ

Assertion : The sensitivity of a moving coil galvanometer is increased by placing a suitable magnetic material as a core inside the coil.

Reason : Soft iron has high magnetic permeability and cannot be easily magnetized or demagnetized.

A
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
B
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
✓
If the Assertion is correct but Reason is incorrect.
D
If both the Assertion and Reason are incorrect.

✓

Answer

Correct option: C.

If the Assertion is correct but Reason is incorrect.

c
Sensitivity of galvanometer

$s\, = \,\frac{\theta }{i} \simeq \frac{{\tan \,\theta }}{i} = \frac{{{\mu _0}N}}{{2R{B_H}}}.$

If a magnetic material is placed inside coil of galvanometer, then

$s\,'\, = \,\frac{{{\mu _r}{\mu _0}N}}{{2R{B_H}}}$

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