Question

A wire is bent in the form of an equilateral triangle of side $100 \,cm$ and carries a current of $2\, A$. It is placed in a magnetic field of induction $2.0 \,T$ directed perpendicular into the plane of paper. The direction and magnitude of magnetic force asting on each side of the triangle will be

• A. 2 N, normal to the side towards centre of the triangle
• B. 2 N, normal to the side away from the centre of the triangle
• C. 4 N, normal to the side towards centre of the triangle
• D. 4 N, normal to the side away from the centre of the triangle

Answer 1

Answer: (C)

$\vec{F} =i(\vec{i} \times \vec{B})$
$=2(1)(2) $
$=4 N$
Nomal to side towards centre of triangle.