The B - H curve for a ferromagnet is shown in the figure. The...

The

B - H

curve for a ferromagnet is shown in the figure. The ferromagnet is placed inside a long solenoid with

1000turns{cm}^{- 1}

. The current that should be passed in the solenoid to demagnetise the ferromagnet completely is

The B - H curve for a ferromagnet is shown in the figure. The ferromagnet is placed inside a long solenoid with

The B - H curve for a ferromagnet is shown in the figure. The ferromagnet is placed inside a long solenoid with

Options

A $2mA$
B $20\mu A$
C $1mA$
D $40\mu A$

Correct answer

C. $1mA$

Step-by-step solution

Coercivity of ferromagnet,

H = 100A / m

n \times I = 100

I = \dfrac{100}{105} = 1mA

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