What is e.m.f. of a cell ? On what factors does its value depend ?

Explanation

E.M.F of a cell :
It is defined as the potential difference between the terminals of a cell in an open circuiti.e. when no current is drawn from the cell.
Factors on which e.m.f of a cell depends :
(i) nature of electrodes (ii) concentration of electrolyte (iii) temperature of the cell (iv) area of electrode immersed in electrolyte (v) nature of electrolyte.