The chopper circuit shown in figure $($i$)$ feeds power to a $5$ A DC constant current source. The switching frequency of the chopper is $100$ kHz $.$ All the components can be assumed to be ideal. The gate signals of switches $S_1$ and $S_2$ are shown in the figure $($ii$).$ Average voltage across the $5$ A current source is

Select one:

a$.10$ V

b$.6$ V

c$.12$ V

d$.20$ V