Lei de Lenz (direção)

Lenz's Law determines the direction of the induced electric current in a closed circuit when there is a change in magnetic flux. It states that the induced current always opposes the change in flux that produced it, generating a magnetic field contrary to the change. This opposition is a consequence of energy conservation, preventing induction from creating energy from nothing. The calculator uses the right-hand rule or the negative sign in Faraday's law to find the correct current direction.

The calculator works simply: you input the direction of the external magnetic field and whether it is increasing or decreasing. The tool then applies Lenz's law to determine the induced current direction. For example, if a magnet approaches a loop, the magnetic flux through it increases; the induced current creates an opposite field, repelling the magnet. The result is shown as clockwise or counterclockwise, or as an induced field vector.

When to use this calculator? In physics problems involving electromagnetic induction, such as exercises with coils, transformers, generators, or magnetic brakes. It is useful for students who need to check direction without sign errors, or for engineers designing circuits where flux opposition is critical. It also helps understand experiments like a magnet falling through a copper tube.

Important cautions: remember that Lenz's law applies only to flux changes, not constant flux. The current direction depends on the circuit orientation (coil winding direction). In systems with multiple turns, the effect accumulates. The calculator assumes uniform magnetic field and no other current sources. For real cases with complex geometries, more detailed simulations are needed.