A bar magnet with its south pole down passes through a conducting ring. As viewed from above the ring, in which direction does the current flow?
To determine the direction of the current flow in the conducting ring when a bar magnet with its south pole down passes through, you can use the right-hand rule for electromagnetic induction. Here's how you can determine the direction:
1. Hold your right hand with your thumb pointing in the direction of the magnetic field created by the south pole of the magnet, which is down in this case.
2. Now, imagine that the conducting ring is in your palm, and your fingers are wrapped around the ring in the direction the magnet is moving.
3. As the magnetic field changes due to the magnet passing through the ring, the flux (amount of magnetic field passing through the ring) changes. According to Faraday's law of electromagnetic induction, this changing flux induces an electromotive force (EMF) that creates an electric current.
4. According to the right-hand rule, the direction of the induced current is perpendicular to both the magnetic field and the motion of the magnet. So, if the magnetic field is down and the magnet is moving downwards, the induced current will flow in a counterclockwise direction when viewed from above the conducting ring.
Therefore, the current flows counterclockwise when viewed from above the conducting ring as the south pole of the bar magnet passes through with its south pole down.