List of top Physics Questions on Magnetism and matter asked in JEE Main

A magnetic needle of magnetic moment $6.7 \times 10^{-2} \, Am^2$ and moment of inertia $7.5 \times 10^{-6} \, kg \, m^2$ is performing simple harmonic oscillations in a magnetic field of $0.01\, T$. Time taken for $10$ complete oscillations is :

Hysteresis loops for two magnetic materials $A$ and $B$ are given below : These materials are used to make magnets for electric generators, transformer core and electromagnet core. Then it is proper to use :

A $25\, cm$ long solenoid has radius $2\, cm$ and $500$ total number of turns. It carries a current of $15\, A$. If it is equivalent to a magnet of the same size and magnetization $|\bar{M}|$ (magnetic moment/volume), then $|\bar{M}|$ is :

A short bar magnet is placed in the magnetic meridian of the earth with north pole pointing north. Neutral points are found at a distance of $30 \,cm$ from the magnet on the East - West line, drawn through the middle point of the magnet. The magnetic moment of the magnet in $Am^2$ is close to : (Given $\frac{\mu_{0}}{4\pi}=10^{-7}$ in SI units and $B_H$ = Horizontal component of earth's magnetic field = $3.6 \times 10^{-5}$ Tesla.)