What is the role of Reactive power in DC supply?

There is no reactive power in  DC power supply. Reactive power is only produce in AC circuits and not in DC circuits.

There is no reactive power in dc circuits because reactive power is produce due to phase difference in ac circuits but which is not in dc circuits .In dc circuits V and I lies at straight line so reactive power in dc circuits is zero.

Adrash ......Is this the only thing you do not know about it.......???????

There is no reactive power for DC power supply. as in case of DC there will be no phase difference between voltage and current than Q=V*I*sin(phase_differnce)=0. 

With Dc power supply, there is no reactive power. Please clarify the purpose of asking such question?????