A coil in the shape of an equilateral triangle of side `l` is suspended between the pole pieces of permanent magnet. Such that `vecB` is in plane of the coil. If due to a current I in the triangle, a torque `tau` acts on it, the side l of the triangel is:

Options

A. `(2)/(sqrt(3))((tau)/(Bi))`
B. `(1)/(sqrt(3))(tau)/(Bi)`
C. `2((tau)/(sqrt(3) Bi))^((1)/(2))`
D. `(2)/(sqrt(3))((tau)/(Bi))^((1)/(2))`

Answer

B

Explanation

`tau=MB=(IA)B=I(sqrt(3))/(4) l^(2)Bimplies l=2((tau)/(sqrt(e)BI))^(1//2)`