Internal Resistance of a cell

“Internal Resistance of a cell” : The resistance applied by the electrolyte inside the cell in the path of flow of current is called internal resistance of a cell.  It is denoted by “r”  and its unit is ohm.

It represent in the circuit as follow

#Factor affecting the internal resistance of cell:

1) Distance between electrodes : The internal resistance of a cell is directly proportional to the distance between the electrodes.

2) Effective area of electrodes: The internal resistance of a cell is inversely proportional to the effective area of the electrodes.

3) Concentration of solution:  Increasing the concentration of solution the number of ions increasing in per unit volume of solution due to which the number of collision between in their mobility increases. Thus internal resistance also increases.

4) Temperature of solution: Increasing the temperature of the solution the kinetic energy of ions increases and internal resistance decreases.

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