Question

State Lenz's Law. In a closed circuit, the induced current opposes the change in magnetic flux that produced it as per the law of conservation of energy. Justify.

Answer 1

1. Opposing the Change: When magnetic flux through a coil changes (due to motion of a magnet or change in magnetic field strength), an induced current is generated. This induced current creates its own magnetic field, which always opposes the original change in flux (as per Lenz's Law).
2. Energy is Conserved: If the induced current did not oppose the change, it would enhance the change, leading to an increase in energy without any external work, which would violate the conservation of energy. or example, if moving a magnet toward a coil aided the change (instead of opposing it), the magnet would accelerate without needing extra energy input—an impossible scenario in real life.
3. External Work is Required: Due to this opposition, external work must be done to move the magnet or change the flux, and this work is converted into electrical energy (induced current), ensuring no energy is created or destroyed.