Question

An elastic circular wire of length \( l \) carries a current \( I \). It is placed in a uniform magnetic field \( \vec{B} \) (Out of paper) such that its plane is perpendicular to the direction of \( \vec{B} \). The wire will experience 

A. No force 

B. A stretching force 

C. A compressive force 

D. A torque

Answer 1

Correct option is (B) A stretching force

We know that,

Magnetic force

F = idl x B,

the magnetic force acts radially outwards. Now if you sum up the effects on all the infinitesimal segments evidently it tries to stretch the wire.