Question

On what factors does the internal resistance of a cell depend?

Hint:

Fresh cells have low internal resistance, but it increases as the cell discharges.

Answer 1

Step 1: Definition.
Internal resistance of a cell is the opposition offered by the electrolyte and electrodes to the flow of charge inside the cell.
Step 2: Factors affecting internal resistance.
1. Distance between electrodes: larger distance $\Rightarrow$ higher resistance.
2. Area of electrodes: larger area $\Rightarrow$ lower resistance.
3. Nature and concentration of electrolyte: higher conductivity $\Rightarrow$ lower resistance.
4. Temperature: increase in temperature generally decreases resistance due to better ionic mobility.
Step 3: Conclusion.
Thus, internal resistance is not fixed but varies with physical and chemical conditions.