$A$ bar magnet is demagnetized by inserting it inside a solenoid of length $0.2 \, m$,$100 \, turns$,and carrying a current of $5.2 \, A$. The coercivity of the bar magnet is.....$A/m$

If the $B-H$ curves of two samples of $P$ and $Q$ of iron are as shown below,then which one of the following statements is $CORRECT$?

The coercivity of a small magnet where the ferromagnet gets demagnetized is $3 \times 10^3 \ Am^{-1}$. 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:

The figure illustrates how $B$,the magnetic flux density inside a sample of unmagnetised ferromagnetic material,varies with $B_0$,the external magnetic flux density in which the sample is kept. For the sample to be suitable for making a permanent magnet:

The figure illustrates how $B$,the flux density,inside a sample of ferromagnetic material varies with external magnetic field $B_0$. For the sample to be suitable for making a permanent magnet,

The magnet can be completely demagnetized by