Q 11-09-055JEE MainJEE Main 2024 (1 Feb, Shift 2)Easy
A big drop is formed by coalescing 1000 small droplets of water. The surface energy will become
Answer: (D) $\dfrac{1}{10}$th
Volume is conserved: $\frac43\pi R^3 = 1000\times\frac43\pi r^3 \Rightarrow R = 10r$.
Surface energy $\propto$ total surface area:
$$\frac{E_f}{E_i} = \frac{4\pi R^2}{1000\times4\pi r^2} = \frac{100r^2}{1000r^2} = \frac{1}{10}$$
Solution by Sreeraj P, M.Sc Physics