When fully discharged, an accumulator battery of emf 6 V possesses an internal resistance of 10 . During the charging process, its internal resistance drops to 1 . The battery, starting from its completely discharged state, is connected to a charger that provides a constant potential difference of 9 V . Calculate the current passing through the battery after a long period once it is completely charged.

Step-by-step solution

The emf of the battery is E = 6 V . The constant potential difference provided by the charger is V = 9 V . When the battery is completely charged, its internal resistance drops to r = 1 . During the charging process, the current I flows into the positive terminal of the battery. The net potential difference driving the current is V - E . Using Ohm's law, the current passing through the battery is given by: I = V - E r Substituting the given values: I = 9 - 6 1 = 3 A