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The coercivity of a bar magnet is 120A//...

The coercivity of a bar magnet is `120A//m`. It is to be demagnetised by placing it inside a solenoid of length `120cm` and number of turns 72. The current (in A) flowing through the solenoid is:

A

4A

B

2A

C

1A

D

zero

Text Solution

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The correct Answer is:
B
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