Question

What is electromagnetic induction and what are its applications?

Answer 1

The term 'Electromagnetic induction' is made up of two words. 'Induction' refers to emf being induced which further causes current to flow. 'Electromagnetic' refers to the two energy systems involved that is Electrical and Magnetic. So the induction of emf is governed by Faraday's Law of Electromagnetic induction (EMI) which states that magnitude of emf is related to change in the flux linked with a coil. If the circuit is closed, a current flows. The direction of emf or current is given by Lenz's Law which ststes that the currnt flows in such a way that the magnetic field it produces opposes the cause behind induction. A simple way to see the process of EMI is by taking a coil connected to a say, a small LED bulb and move a magnet around it, As the distance of magnet from the coil changes, the magnetic field linking the coil changes and this leads to emf induction and the LED lights up. APPLICATIONS: In the simple example stated above, we can see the potential of EMI to generate electrical energy. Hence it is the principle behind ELECTRICITY GENERATORS. The reson this is so important for a generator is because it has a rotating part which has to generate electricity in a stationary part. Hence it cannot be in contact. Magnetism being a non-contact force allows for transmission of energy without contact. The same principle is also used in TRANSFORMERS and INDUCTION MOTORS, the most common form of motors used in our homes and even to run trains and in big industries.