Electromotive Force EMF - Definition, Unit, Circuit Diagram

In this post you will learn about electromotive force vs voltage, electromotive force formula, electromotive force definition physics, electromotive force application

EMF is the short form of electromotive force.

All the metals contain a large number of free electrons which move randomly in all the directions, inside the metal piece, if no external source is connected.

If a battery or voltage source is connected across a metal piece as shown in Fig. then the free electrons will move in the direction of positive end of the external de source. This happens due to the electric force or pressure by the external battery.

Definition 

The electrical force or pressure that causes the electrons to move in a particular direction is called as the electromotive force EMF

Unit

The units of e.m.f. is volts and e.m.f. is also called as voltage or potential difference. It is denoted by V or sometimes by E.