A conducting circular loop of radius r carries a constant i. It is placed in a uniform magnetic field B such that B is perpendiclar to the plane of thre loop is .What is the magnetic force acting on the loop?

Options

A. `irB`
B. `2piirB`
C. `zero`
D. `piirB`

Answer

C

Explanation

The magnetic force acting on the loop is zero. Because the magnetic field produced by the current in the loop and the external magnetic field are equal and opposite and they act in the same line.