Question

The storage battery of a car has an emf of 12 V. If the internal resistance of the battery is 0.4Ω, what is the maximum current that can be drawn from the battery?

Answer 1

Emf of the battery, E = 12 V
Internal resistance of the battery, r = 0.4 Ω
Maximum current drawn from the battery = I
According to Ohm’s law,
$E = Ir$
$I = \frac{E}{r}$
$I = \frac{12}{0.4}$
I = 30 A
The maximum current drawn from the given battery is 30 A