The charge flown through a circuit in the time interval between `t and t+dt` is givne by `edq=e^(-t/tau)dt,` where `tau` is a constnt. Find the total charge flown through the circuit betweent `t=0 to t=tau`.

Explanation

The totla charge flown is the sum of all the dq's for t varying from t=0 to `t=t_0`. Thus, the total charge flown is
`Q=inttau_0 e^(-t/tau)dt`
`=[(e^(-t/tau))/(-1/tau)]^tau_0=tau(1-1/e)`