A network of uncharged capacitors and resistances is shown Current through the battery immediately after key K and after a long time interval is :
Let the current in the circuit is I.
Just after the key is closed the capacitor can be replaced as a short circuit.
The current is given as,
I=ER1
After long time capacitor does not allow current to pass through it, so capacitor can be replaced as open circuit.
The current can be written as,
−E+IR1+IR3=0
I=ER1+R3