Current Electricity | Case Study-01
Case Study
(Relation Between V, E and r of a Cell)
General Instructions
Electric Cell | EMF | Terminal Voltage
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Relation Between V, E and r of a Cell-
Emf of a cell is the maximum potential difference between two electrodes of the cell when no current is drawn from the cell. Internal resistance is the resistance offered by the electrolyte of a cell when the electric current flows through it. The internal resistance of a cell depends upon the following factors-
- distance between the electrodes
- nature and temperature of the electrolyte
- nature of electrodes
- area of electrodes
For a freshly prepared cell, the value of internal resistance is generally low and goes on increasing as the cell is put to more and more use. The potential difference between the two electrodes of a cell in a closed circuit is called terminal potential difference and its value is always less than the emf of a cell in a closed circuit. It can be written as V = E – Ir.
