Efficiency of a Source—

The efficiency of a source is defined as the ratio of the output power to the input power.

Let a voltage source of emf ‘E’ and internal resistance ‘r’ is connected to the resistance ‘R’ so that current ‘I’ is flowing through it, then efficiency

Efficiency of an Electrical Device—

The device which converts electrical energy to mechanical or heat energy is called electrical device and the ratio of the output power produced by it to the energy consumed by it is called its efficiency.

Application of Heating effect of Current—

1. Electric Bulb
2. Electric Fuse
3. Electric Arc
4. Electric Toaster
5. Electric Iron