A capacitor of capacitance as C is given a charge Q. At `t=0`,it is connected to an ideal battery of emf `(epsilon)`through a resistance R. Find the charge on the capacitor at time t.

Answer

C

Explanation

`q_i=q_0`
`q_f=EC`
Now, charge on capacitor change from `q_i` to `q_f` exponentially.

`:. q=q_0+(EC-q_0)(1-e^(-1/tau_C))`
`=EC(1-e^(-t/tau_C))+q_0e^(-t/tau_C))`
Here `tau_C=CR`