Sign and Sense of an Induced Electric Current by a Nearby Moving Magnet

Abstract

In one of the Faraday’s experiments an electric current is induced in a conducting loop when a magnet in front of it moves towards or away from the loop. While the direction of circulation of the electric current in the loop has only two options, it depends on three experimental conditions that generate eight cases. Even though the Faraday law or the Lenz law by itself answers for the current sense in each case, we think that a graphic synthesis of all the cases and its corresponding result is a new and interesting exercise we want to discuss. The resulting diagram is a starting point for other exercises on the induced current that a teacher might propose to their students in introductory college physics.