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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

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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