Question:
A wire loop as well as a bar magnet lie in one and the same horizontal plane. The bar magnet is exterior of the loop. The bar magnet is rotating at a constant rate counter clockwise about a vertical axis through the centre of the bar magnet. Consider an immediate when the north pole of the bar magnet has just passed its closest point of approach to the loop and is distancing itself from the loop. At that immediate what is the direction of the current if any induced to flow in the loop?
Answer:
Even though the magnetic field at the location of the loop is indeed changing none of the magnetic field lines pass through the loop at any time. The magnetic field lines rally the loop edge on. The numerous magnetic field lines passing through the loop is zero and it never changes. Because it takes a changing number of magnetic field lines through the loop to induce a current to flow in the loop there is no current in the loop.