Induced e.m.f is given by it will be maximum when,
Faraday's Law of Electromagnetic Induction
If be the magnetic flux linked with a circuit at any time then the laws of electromagnetic induction can be expressed mathematically as
Where is the induced emf. Here it is important to point out that does not depend on how the flux is changed.
If the electric field in space is denoted by then, by definition, the emf around a closed path is
If is an open surface bounded by the curve placed in a magnetic field then the magnetic flux through the surface is
So equation can be written as
This is the integral form of Faraday's law.
Therefore, from equation we can see that for maximum emf, the angle between and must be .
Hence, for maximum induced emf the open surface must be parallel to the magnetic field.