internal resistance cell

Question

Terminal voltage V of cell with emf E and internal resistance r delivering current I?

RankGuru · Accepted Answer

1. **Concept**: Every real cell has some resistance to the flow of current within it, known as internal resistance ($r$).
2. **Internal Voltage Drop**: When a current $I$ flows through the cell, some potential is lost overcoming internal resistance. This 'lost volt' is equal to $Ir$.
3. **Definition**: The potential difference across the terminals ($V$) is the net voltage available after this internal loss.
4. **Formula**: $V = E - Ir$ (while discharging).
5. **Note**: If the cell were being charged, the terminal voltage would be $V = E + Ir$.

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internal resistance cell

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