An isolated capacitor of unknown capacitance has been charged to potential `V_(0)`. This capacitor is then connected to an uncharged capacitor of capacity `C`. If common potential is `V(ltV_(0)`, find unknow capacitance.

Explanation

Let the capacitance of first capacitor be `C_(0),`
`C_(1)=C_(0), V_(1)=V_(0), C_(2)=C, V_(2)=0, V=V`
common potential:
`V=(C_(1)V_(1)+C_(2)V_(2))/(C_(1)+C_(2))`
`=(C_(0)V_(0)+Cxx0)/(C_(0)+C)`
`C_(0)V+CV=C_(0)V_(0)impliesCV=C_(0)(V_(0)-V)`
`C_(0)=(CV)/(V_(0)-V)`