Question:
The internal resistance of an accumulator battery of emf $6 \mathrm{~V}$ is $10 \Omega$ when it is fully discharged. As the battery gets charged up, its internal resistance decreases to $1 \Omega$. The battery in its completely discharged state is connected to a charger which maintains a constant potential difference of $9 \mathrm{~V}$. find the current through the battery.
(a)Just after the connections are made and
(b) After a long time when it is completely charged.
Solution:
