Find the time dependence of the current flowing through the inductance `L` of the circuit shown in Fig after the swich `Sw` is shorted at the moment `t = 0`.

Explanation

Clearly `L = (di)/(dt) = R (I - i) = xi - RI`
so, `2L (di)/(dt) = xi -Ri`
This equaction has the solution (as in 3.312)
`I = (xi)/(R) (1 - e^(-t R//2L))`