Question

Current i is passed through an inductor. For the given situations, inductor will behave as:

Solution

When (di)/(dt) is positive, current is increasing with time. Inductor will oppose the flow of the current according to Lenz's law. So, inductor behaves like I.

When (di)/(dt) is negative, current is decreasing with time. Inductor will support the flow of the current according to Lenz's law. So, inductor behaves like II.

Therefore, option (a) and (d) are correct.