Sixty four conducting drops each of radius \( 0.02\,\text{m} \) and each carrying a charge of \( 5\,\mu\text{C} \) are combined to form a bigger drop. The ratio of surface density of bigger drop to the smaller drop will be:
\( 1 : 4 \)
\( 4 : 1 \)
\( 1 : 8 \)
\( 8 : 1 \)