The B-H curve for a ferromagnet is shown in the figure. The ferromagnet is placed inside a long solenoid with 1000 turns cm- 1 . The current that should be passed in the solenoid to demagnetise the ferromagnet completely is

Question

The B-H curve for a ferromagnet is shown in the figure. The ferromagnet is placed inside a long solenoid with 1000 turns cm- 1 . The current that should be passed in the solenoid to demagnetise the ferromagnet completely is <img class="img-fluid question-image" alt="Question" src="https://cdn.tardigrade.in/q/nta/p-5the4tjxiyly.png" /> (A) 2mA (B) 20μA (C) 1mA (D) 40μA

Tardigrade Admin · Accepted Answer

Coercivity of ferromagnet, H=100A/m . n× I=100 I=(100/105)=1 mA

Q. The $B - H$ curve for a ferromagnet is shown in the figure. The ferromagnet is placed inside a long solenoid with $1000 t u r n s c m^{- 1}$ . The current that should be passed in the solenoid to demagnetise the ferromagnet completely is

$2 m A$

$20 μ A$

$1 m A$

$40 μ A$

Coercivity of ferromagnet, $H = 100 A / m$ .
$n \times I = 100$
$I = \frac{100}{1 0 ^{5}} = 1 m A$

Q. The B−H curve for a ferromagnet is shown in the figure. The ferromagnet is placed inside a long solenoid with 1000turnscm−1 . The current that should be passed in the solenoid to demagnetise the ferromagnet completely is

2mA

20μA

1mA

40μA