A conducting loop is held below a current-carrying wire PQ as shown. Predict the direction of the induced current in the loop when the current in the wire is constantly increasing.
Answer: The induced current in the loop is anticlockwise.
Solution
The current in PQ produces a field into the plane of the loop (below the wire). As the wire current increases, this inward flux through the loop increases. By Lenz's law the loop opposes the increase by setting up flux out of the plane inside the loop. By the right-hand rule, flux out of the plane requires an anticlockwise induced current in the loop.
