NEET Physics Magnetic Effects of Current and Magnetism MCQs

A short bar magnet of magnetic moment $M$ is placed in a non-uniform magnetic field $B$. If the gradient of the field is $\frac{dB}{dx}$ along the axis of the magnet, the force on the magnet is:

Two identical short bar magnets, each of magnetic moment $M$, are placed perpendicular to each other at a distance $d$ apart. The magnetic field at a point midway between them on the line joining their centers is:

A magnetic dipole of moment $M$ is aligned at an angle $heta$ with a uniform magnetic field $B$. The work done in rotating it by an angle $dheta$ is:

A short bar magnet placed with its axis at 30° with an external field of 800 G experiences a torque of 0.016 Nm. The magnetic moment of the magnet is:

Two coaxial circular loops of radii 'a' and 'b' (b > a) carry currents $I_1$ and $I_2$ respectively in opposite directions. The loops are separated by a distance 'd' which is much larger than both 'a' and 'b' (d >> a, b). The magnetic field at a point on the axis, at a distance 'x' from the center of the smaller loop (x >> a, b) can be approximated by:

A current carrying loop behaves like a:

A bar magnet is cut into two equal halves along its length. The magnetic dipole moment of each half is:

Which of the following materials has permanent magnetic dipoles?

A magnet is parallel to a uniform magnetic field. If it is rotated by $60^\circ$, the work done is 0.8joules. How much additional work is done in moving it $30^\circ$ further

Two small bar magnets are placed in a line with like poles facing each other at a certain distance $d$ apart. If the length of each magnet is negligible as compared to $d$, the force between them will be inversely proportional to