Question

Magnetic field at far axial point due to solenoid as well as bar magnet varies ______.

Options

• inversely as R square, where R = axial distance to the magnet/solenoid

• directly as R squared, where R = axial distance to the magnet/solenoid

• inversely as cube of R, where R = axial distance from the magnet/solenoid

• directly as R cubed, where R = axial distance to the magnet/solenoid

Answer 1

Magnetic field at far axial point due to solenoid as well as bar magnet varies inversely as cube of R, where R = axial distance from the magnet/solenoid.

Explanation:

Magnetic field at far off-axial point due to a bar magnet as well as solenoid is given by `mu_0/(4pi) (2vec"m")/"R"^3`, where m is magnetic moment and R is distance of axial point.