A metallic rod of mass per unit length is lying horizontally on a smooth inclined plane which makes an angle of with the horizontal. The rod is not allowed to slide down by flowing a current through it when a magnetic field of induction is acting on it in the vertical direction. The current flowing in the rod to keep it stationary is:
- A
- B
- C
- D
Solution & Step-by-step Explanation
For the rod to remain stationary on the smooth incline:Component of gravity down the incline .Magnetic force on the rod .Since is vertical, the horizontal magnetic force is directed such that its component up the incline balances gravity.The force balance along the incline: .
Substitute the values: .
Substitute the values: .