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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 a solenoid of length 10 cm and number of turns 100, so that the magnet gets demagnetized when inside the solenoid is:

A

`3A`

B

`6A`

C

`30 mA`

D

`60 mA`

Text Solution

Verified by Experts

The correct Answer is:
A
`H=nl`
`therefore H= (NI)/(l)" "[because n= (N)/( l)]`
`therefore I= (Hl)/( N)`
`=3 xx 10^(3) xx (0.1) /( 100)`
`therefore I=3A`
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