# Working Principle of Transformer – Single Phase Transformer – Basic Electrical Engineering

Hello friends in this video we are going to see basic working principle of a transformer so transformer works on the principle of mutual induction so here we need to define what is this concept called as mutual induction is so mutual induction I define the principle of mutual induction states that when two coils are inductively coupled and if current in one coil change uniformly then an EMF gets induced in the other coil so what they’re saying suppose I’m placing 2 coils together without having any electrical connections between them that is what it is called as inductively coupled and I am exerting one of the coil by giving AC supply so what will happen EMF will get induced at the secondary side this concept is called as mutual induction so what happened basically that I will explain with the help of basic transformer diagram it is like this so in this structure this is a magnetic core on this core 2 coils are wound like this this coil we called as a primary winding and this winding or this coil is called as secondary winding now how to decide primary and secondary winding wherever there is a supply connected that coil is called as a primary winding and wherever load is connected that coil is a secondary winding now because of this AC supply current will pass through this this current will give rise to magnetic flux which will pass through this magnetic core like this so this is magnetic flux phi but now what happen this magnetic flux which is changing with respect to time gets linked with a primary winding and will give rise to EMF by Faraday’s law of electromagnetic induction and that EMF is called as self induced EMF what is the self induction I am getting a voltage because of a supply which is connected to same coil but at the secondary side what would happen same flux is linked with a secondary winding also so it is flux which is changing with respect to time gets linked with the secondary coil give rise to an EMF this EMF have got induced because of the supply which is there at the primary side therefore it is called as a mutually induced EMF and if I connect the secondary winding through load current will pass through the secondary side also so this is what the principle of mutual induction so I have explained that concept with the help of a basic transformer now how this basic transformer can be represented so I am going for symbolic representation so it’s very simple AC supply is connected to primary winding there is a magnetic core and secondary winding is connected to load it’s a primary winding this is a secondary winding this is load AC supply this is N 1 turns this these are N 2 turns here we have seen what is the working principle of a transformer and that is nothing but mutual induction mutual induction is nothing but getting the EMF at the secondary side because of the supply at the primary side so this is what the concept of mutual induction which is nothing but working principle for a transformer thank you