Discussion Forum



1)

A conducting circular loop of,radius r carries a constant current i. It is placed in a uniform magnetic field $\bar{B}_{0}$  such that

$\bar{B}_{0}$ is perpendicular to the plane of the loop. The magnetic force acting on the loop is


A) $irB_{0}$

B) $2\pi irB_{0}$

C) Zero

D) $\pi irB_{0}$

Answer:

Option C

Explanation:

The magnetic field is perpendicular to the plane of the paper. Let us consider two diametrically opposite elements. By Fleming's Left-hand rule on element AB the direction of force will be Leftwards and the magnitude will be

dF= ld/ B sin 90° = Id/B

1952021102_203847_167639_ans.jpg

On element CD, the direction of force will be towards right on the plane of the paper and the magnitude will be dF = Id/B.