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 immediately after the circuit is connected.

Step-by-step solution

The current I passing through a battery during the charging process is given by the relation V = E + Ir , where V is the potential difference provided by the charger, E is the emf of the battery, and r is its internal resistance. Immediately after the circuit is connected, the battery is still in its completely discharged state. Therefore, the internal resistance of the battery is r = 10 . Substituting the given values V = 9 V , E = 6 V , and r = 10 into the formula: I = V - E r I = 9 - 6 10 I = 3 10 = 0.3 A