Explain how Lenz's law works?

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Detailed Solution

Lenz’s law says the induced current in a circuit flows in a direction that opposes the change in magnetic flux that produced it. In short, induced effects resist the cause.

Core relation

EMF (E) = - d(phi)/dt. The minus sign encodes the opposition.
phi is magnetic flux through the circuit.

Intuitive cases

Push a magnet toward a loop: flux increases. The induced current makes a magnetic field that pushes back.
Pull the magnet away: flux decreases. The induced current makes a field that tries to keep the magnet near.

Real-world outcomes

Energy conservation: The work you do appears as electrical energy and heat.
Eddy currents: Solid metals build circulating currents that oppose motion, giving magnetic braking and induction heating.
Back EMF: Motors generate an opposing voltage as they speed up, limiting current.

Applications