Equation holds good only if the magnetic field is uniform over the surface.
If the magnetic field varies,then the surface is divided into number of area elements,each of which has area small enough so that magnetic field is constant through each of the areas.Let be the area of a small element,then the magnetic flux through the elements is given by
Faraday’s First law of Electromagnetic Induction
Faraday’s Second law of Electromagnetic Induction
Fleming’s Right Hand Rule
Methods of Producing Induced e.m.f.
SI Unit of self inductance is henry (H)
Spark is produced in the electric switch when the light is switched off.
When the circuit is switched off, the current in the circuit begins to decrease rapidly. As a result of this, a large induced e.m.f. is set up across the switch contacts which tries to maintain the current. This e.m.f. is sufficient to break down the insulation of the air between the switch contacts and hence spark is produced.
An ideal Inductor has high value of self inductance and zero ohmic resistance.
Energy stored in an Inductor
oportional to the current flowing through the primary coil i.e.
SI unit of mutual inductance is henry (H).