The effective radius of a circular coil is R and number of turns is N. The current through it is i a
Channel: Doubtnut
Date: 2020-01-26

The effective radius of a circular coil is R and number of turns is N. The current through it is i ampere. The work done is rotating the coil from angle `theta = 0^(@)` to `theta = 180^(@)` in an external magnetic field B will be -