An inductor-resistor-battery circuit is switched on at t = 0. If the emf of battry is `epsilon` find the charge passes through the battery in one time constant `tau`.
Options:
(a) `(i_(max)tau)/e`
(b) `(tau-1)e' 'i_(max)`
(c) `(i_(max))/e`
(d) `tau i_max`