Working Principle of Transformer
Transformer is a static device works on the principle of electromagnetic (mutual) induction. When an A.C supply is given to the primary of transformer an alternating flux is set up in transformer core. As both primary and secondary windings are wounded over the core, a primary induced emf e1 is induced in the primary winding and secondary induced emf e2 is induced in the secondary winging.
Due to emf e2 a current i2 will flow towards the load. E1 and e2 depends on the primary and secondary number of windings N1 and N2. If N1 is greater than N2, V1 will be greater than V2 under this condition transformer will work as step-down transformer vice-versa If N2 is greater than N1, V2 will be greater than V1 under this condition transformer will work as step-up transformer.