A metallic rod of mass per unit length \(0.5\; kg\; m^{-1}\) is lying horizontally on a smooth inclined plane which makes an angle of \(30^o\) with the horizontal. The rod is not allowed to slide down by flowing a current through it when a magnetic field of induction \(0.25\; T\) is acting on it in the vertical direction. The current flowing in the rod to keep it stationary is.....\(A\)

Apply the relevant identity from the chapter and substitute the values established in the previous step, keeping the original constraint in view.

Use the simplified expression to isolate the unknown, then plug the result back into the question setup to confirm the working is internally consistent.

Cross-check against a boundary or limiting case. Both the dimensional balance and the qualitative behaviour at the extreme should agree with the candidate answer.

Combine the steps above to identify the correct option. The remaining choices each fail at least one of the consistency, dimensional, or boundary checks.