CBSE Class 12-science Answered

The above circuit operates in two states:

1)      Transient state i.e. at the time just after the switch ‘S’ is closed and

2)      Steady state

Transient state: When the switch ‘S’ is closed, the current starts flowing through both the resistors and the capacitor starts charging.

If at any instant the charge across the capacitor plates is ±q, then the potential difference across the capacitor of capacitance is given by

Now applying KVL to the loop ABEFA

applying KVL to the loop ABCDEFA

Steady state: At steady state, the capacitor gets fully charged and it acts as open circuit. 

Therefore the circuit is modified as given below:

now applying KVL to loop ABCDEFA