Question

What is the difference between EMF of A cell,TERMINAL POTENTIALAND SUPPLY VOLTAGE.ARE SUPPLY VOLTAGE AND TERMINAL POTENTIAL NOT THE SAME?

Answer 1

Terminal voltage is the potential difference across the terminals of a load when the circuit is switched on.

E.m.f. is the maximum potential difference that can be delivered by a cell or a generator when no current flows through it.

Terminal voltage is measured by voltmeter.

E.m.f. is measured by potentiometer.

Terminal voltage is always lesser than the emf of the cell. It is because of the drop in potential because of the current passing through the internal resistance of the cell or the generator. Emf (E) and terminal (V) is related by the following equation.

E = V + Ir Where I = current and r = internal resistance of the cell.