Question

A triangular loop of side `l` carries a current I. It is placed in a magnetic field B such that the plane of the loop is in the direction of B. The torque on the loop is ____________.

Options

• zero

• `"IB"l`

• `sqrt3/2"I"l^2"B"^2`

• `sqrt3/4"IB"l^2`

Answer 1

A triangular loop of side `l` carries a current I. It is placed in a magnetic field B such that the plane of the loop is in the direction of B. The torque on the loop is `sqrt3/2"I"l^2"B"^2`.

Explanation:

`"for"  theta = 90°,`

`"Area of equilateral triangle" = sqrt3/4l^2`

`Rightarrow tau = "NIAB" = 1 xx I xx (sqrt3/4l^2)"B"` 

`= sqrt3/4l^2 "BI"`