How to Use Lenz’s Law to Determine Direction of Induced Current

To determine direction of induced current, we can apply Lenz’s Law in two different ways.

First is the opposition to pole movement. The approach of the magnet’s North Pole increases flux through the loop and this induces current in the loop and therefore the loop acts as a magnetic dipole with a South Pole and a North Pole. To oppose the magnetic flux increase by the approaching magnet, the loop’s North Pole must face toward the approaching magnet’s North Pole in order to repel it. The current induced in the loop described must be COUNTERCLOCKWISE.

Second is the opposition to flux change. With initially distant magnet, no magnetic flux passes through the loop itself. When the North Pole of the magnet approaches the loop with its magnetic field directed downward, the flux through the loop increases. To oppose the increase in flux, the induced current must create an induced magnetic field directed upward inside the loop. The induced current in the loop described must be COUNTERCLOCKWISE.

 

  • Subject : Science
  • Topic : Physics
  • Posted By : Jason
  • Created on : 04-12-2013

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