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The coercitivity of a small magnet where...

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

A

30 mA

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, `rArr3xx10^(3)=100/(0.1)xxIrArrI=3A`
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