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 demagnetize 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

Options

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

Correct answer

C. $1mA$

Step-by-step solution

The coercivity of ferromagnet,

H = 100A{m}^{- 1}

n \times I = 100

⇒ I = \dfrac{100}{{10}^{5}} = 1mA

Practice Magnetic Properties of Matter on Quantrex Academy →

More from Magnetic Properties of Matter

A solenoid has a core made of material with relative permeability 400 . The magnetic… JEE Main 2026 Two identical small bar magnets each of dipole moment 3 5 J/T are placed at a center to… JEE Main 2026 Given below are two statements: one is labelled as Assertion (A) and the other is… JEE Main 2026 Given below are two statements : one is labelled as Assertion (A) and the other is… JEE Main 2025 The percentage increase in magnetic field (B) when space within a current carrying… JEE Main 2025 A solenoid having area A and length ' l ' is filled with a material having relative… JEE Main 2025 The relationship between the magnetic susceptibility (χ) and the magnetic permeability… JEE Main 2025 A bar magnet has total length 2 l=20 units and the field point P is at a distance d=10… JEE Main 2025 Full Magnetic Properties of Matter list All JEE Main PYQs