Question

When a cell is short-circuited (R = 0), the maximum current that can flow is:

Options

• \[I_{max} = ε + r\]

• \[I_{max} = ε \cdot r\]

• \[I_{max} = \frac{r}{ε}\]

• \[I_{max} = \frac{ε}{r}\]

Answer 1

At short circuit, external resistance R becomes zero, so the current formula \[I = \frac{ε}{R + r}\] reduces to \[I_{max} = \frac{ε}{r}\]. This represents the theoretical maximum current limited only by the cell's internal resistance. The maximum current is inversely proportional to internal resistance.