In a boost chopper circuit if Vs, V0, L are input voltage, output voltage and inductance, respectively, and when the conducting switch is opened, the rate of change of inductive current is
1
\(\frac{{{V_s}}}{L}\)
2
\(\frac{{{V_0}}}{L}\)
3
\(\frac{{{V_s} - {V_0}}}{L}\)
4
\(\frac{{{V_s} + {V_0}}}{L}\)