A current loop consist of two straight segments (OA and OB), each of length , having an angle `theta` between them and a semicircle (ACB). The loop is placed on an incline plane making an angle `theta` with horizontal (see figure). The loop carries a current I. A uniform vertical magnetic field B is switched on. (a) Write the value of magnetic torque on the loop. (b) Tell whether the normal contact force between the incline and the loop increases or decreases when magnetic field is switched on. Assume that the loop remains stationary on the incline.

Answer

`(a) tau=Ibl^(2)sintheta.sin theta/2[cos theta/2+pisintheta/2]`
(d) No change