3.1 The storage battery of a car has an emf of 12 V. If the internal resistance of the battery is 0.4 , what is the maximum current that can be drawn from the battery?
Emf of battery, E = 12 V
Internal Resistance of Battery, r = 0.4
Let I be the maximum current drawn from the battery.
We know, According to Ohm's law:
E = Ir
I = E/r = 12/0.4
I = 30 A
Hence the maximum current drawn from the battery is 30 A.