d
(d) \({Q_1} = {10^{ - 2}}C\), \({Q_2} = 5 \times {10^{ - 2}}\,C\)
Total charge of the system \( Q = 6 \times {10^{ - 6}}\,C\)
Charge on small sphere
\(Q{'_1} = \frac{{Q\,{r_1}}}{{{r_1} + {r_2}}} = \frac{{6 \times {{10}^{ - 2}} \times 1}}{{1 + 2}} = 2 \times {10^{ - 2}}\,C\)