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The coercivity of a small magnet where t...

The coercivity of a small magnet where the ferromagnet gets demagnetized is `3 xx 10^(3) Am^(-1)`. The current required to be passed in solenoid of length 10 cm and number of turns, 100, so that the magnet gets demagnetized when inside the solenoid , is :

A

`30mA`

B

`60 mA`

C

`3A`

D

`6A`

Text Solution

Verified by Experts

The correct Answer is:
C
For solenoid, the magnetic field needed to be magnetized the magnet. `B= mu_0 nI`
where ,`implies 3 xx 10^3 =( 100 )/( 0.1 ) xx I implies 3A `
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