Question

why does internal resistance increase with increase in length of electrodes?

Answer 1

Dear student,
When the electric current flows through the cell, the resistance offered by the electrolyte of the cell is known as internal resistance of the cell. It is denoted by r. Internal resistance of a cell can be measured by potentiometer. For a new cell, the value of internal resistance is very low but as the cell is put to more use, its internal resistance goes on increasing.

The internal resistance of a cell depends upon

the distance between the electrodes( increases with the increase in distance) the nature of the electrolyte the nature of electrodes the area of the electrodes immersed in the electrolyte. The internal resistance of the cell is inversionally proportional to the area of the electrodes, i.e. if area is increased, internal resistance will decrease.

So it is the distance between the electrodes and not the length of the electrodes.

Regards