A current carrying closed loop in the from of a right angle isoseles triangle `ABC` is placed in a unifrom magnetic fild acting along `AB`. If the magnetic force on the arm `BC` is `F`, the force on the arm `AC` is

Options

A. `- sqrt2 vec F`
B. `- vec F`
C. `vec F`
D. `sqrt 2 vec F`.

Answer

b

Explanation

Since the current loop is placed in a uniform magnetic field, the net force acting on the loop will be zero.
The arm AB of the loop is parallel to magnetic field, so no force will act on this arm. Therefore, the magnetic force on AC must be `- vec F` , so that the net magnetic force becomes zero.