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Driving Question: How does Lenz law and Eddy current work?

Introduction

Lenz's law is a common way of understanding how electromagnetic circuits obey Newton's third law and the conservation of energy. Lenz's law is named after Heinrich Lenz, and it says: If an induced current flows, its direction is always such that it will oppose the change which produced it. Lenz's law is shown with

the negative sign in Faraday's law of induction:

which indicates that t

he induced voltage (ℰ) and the change in magnetic flux (∂Φ) have opposite signs. Lenz's Law is a qualitative law that refers to the direction of induced current in relation to the effect which produces it without quantitatively relating their magnitudes.

For a rigorous mathematical treatment, see electromagnetic induction and Maxwell's equations.

Scientific Principle

If a change in the magnetic field of current i₁ induces another electric current, i₂, the direction of i₂ is opposite that of the change in i₁. If these currents are in two coaxial circular conductors ℓ₁ and ℓ₂ respectively, and both are initially 0, then the currents i₁ and i₂ must counter-rotate. The opposing currents will repel each other as a result.

Lenz's law states that the current induced in a circuit due to a change or a motion in a magnetic field is so directed as to oppose the change in flux and to exert a mechanical force opposing the motion.

MATERIAL

-Copper tube

-Small Magnet

-Small metal sphere