Question

State Faraday’s law of electromagnetic induction.

Hint:

Faraday's Law: \[ e=-N\frac{d\phi_B}{dt} \] The negative sign represents Lenz's law, which states that the induced current always opposes the change in magnetic flux producing it.

Answer 1

Concept: Electromagnetic induction is the phenomenon of production of an emf in a conductor or circuit whenever the magnetic flux linked with it changes. This phenomenon was discovered experimentally by Michael Faraday and forms the basis of electric generators, transformers, induction motors and many other electromagnetic devices. Faraday's First Law of Electromagnetic Induction: Whenever the magnetic flux linked with a closed circuit changes, an emf is induced in the circuit. If the circuit is closed, an induced current also flows through it. Faraday's Second Law of Electromagnetic Induction: The magnitude of the induced emf is equal to the negative rate of change of magnetic flux linked with the circuit. For a single turn coil, \[ \boxed{ e=-\frac{d\phi_B}{dt} } \] where \[ \phi_B=\text{magnetic flux linked with the circuit}. \] For a coil having \(N\) turns, \[ \boxed{ e=-N\frac{d\phi_B}{dt} } \] The negative sign represents Lenz's law and indicates that the induced emf always opposes the cause producing it. Final Statement: \[ \boxed{ e=-N\frac{d\phi_B}{dt} } \] Thus, the induced emf in a circuit is equal to the negative rate of change of magnetic flux linked with the circuit.