$A$ 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.....$A/m$

$A$ metal rod is subjected to cycles of magnetisation at the rate of $42 \ Hz$. The density of the metal is $6 \times 10^3 \ kg \ m^{-3}$ and its specific heat capacity is $0.1 \times 10^3 \ cal \ kg^{-1} \ ^{\circ}C^{-1}$. If the area of its $B-H$ loop corresponds to an energy density of $10^{-2} \ J \ m^{-3}$,then the rise in its temperature in one minute is: (in $^{\circ} C$)

The only property possessed by ferromagnetic substances is

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:

Which of the following statements is incorrect about hysteresis?

The area of the hysteresis loop of a substance indicates: