Question

A water drop of radius $1 \,cm$ is broken into $729$ equal droplets If surface tension of water is $75 \,dync / cm$, then the gain in surface energy upto first decimal place will be : [Given $\pi=314]$

• A. $8.5 \times 10^{-4} J$
• B. $8.2 \times 10^{-4} J$
• C. $7.5 \times 10^{-4} J$
• D. $5.3 \times 10^{-4} J$

Answer 1

Answer: (C)

$7.5 \times 10^{-4} J$

Answer 2

The correct option is(C): $7.5 \times 10^{-4} J$.