Reactance
An ac voltage v = vm sinωt applied to a pure inductor L, drives a current in the inductor i...
Alternating current (AC) & Alternating Voltage
Alternating current (AC)
An alternating current is one whose magnitude changes sinusoidally with time. Thus alternating current is given by
Where i0=current amplitude or peak value...
Mutual Induction
Whenever there is a change in the magnetic flux linked with a coil, there is also a change of flux linked with the neighbouring...
Self Induction
The property of a coil which enables to produce an opposing induced emf in it when the current in the coil changes is called...
Eddy Currents
When large pieces of conductors are placed in changing magnetic flux, small circulating currents are induced in them. These currents are called eddy currents...
Induced EMF and Current – Electromagnetic Induction
Whenever there is a change in the magnetic flux linked with a closed circuit an emf is produced. This emf is known as the...
Lenz’s law of Electromagnetic Induction
Lenz’s law states that the polarity of the induced emf is such that it tends to produce a current which opposes the change in...
Faraday’s Laws of Electromagnetic induction
Michael Faraday demonstrated the reverse effect of Oersted experiment. He explained the possibility of producing emf across the ends of a conductor when the...
Permanent Magnets and Electromagnets
Substances which at room temperature retain their ferromagnetic property for a long period of time are called permanent magnets. Permanent magnets can be made...
Ferromagnetic Substances
Ferromagnetic substances are those which develop strong magnetization in the direction of the magnetizing field. They are strongly attracted by magnets and tend to...