Question

What is Faraday’s Law? What two things does it relate?

What is Lenz’s Law? What does it conserve?

In the early 1830’s physicist Michael Faraday discovered magnetic induction. In his experiment, emf was induced in a coil of wire by a bar magnet. What did Faraday observe when the magnet is at rest and when it is moving?

Answer 1

1) On the basis of experimental evidences, faraday gives the following laws of electromagnetic induction.

Fisrt law :-

Whenever there is a change of magnetic flux near a closed circuit, an emf is induced in the circuit.

Second law :-

The magnitude of induced emf in the circuit is directly proportional to the rate of change of magnetic flux associated with the circuit.

mathematically it is represented as

2) this law relate induced emf in the circuit and magnetic flux associated with the circuit.

3) Lenz's law gives the direction of an induced current in the circuit.statement of Lenz's law is

Lenz's law :-

The direction of induced current in a circuit is such that the magnetic filed produced by current in a circuit opposes the change in the magnetic flux that induces the current.

4) Lenz's law conserve the law of conservation of energy.

5) Faraday's Experiment :-

He makes a coil by wrapping a wire on a paper cylinder. he connected the two end of coil to the galvanometer. then he moved a bar magnet back and forth inside the cylinder.

when he kept the bar magnet at rest he found that needle of galvanometer was not moving and it was at zero.

When he moved magnet back and forth inside the cylinder he found that needle of galvanometer moves.

from above observation Faraday's confirmed that a moving magnet incuses emf in the coil.