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Surface energy of a liquid - class-XI

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What is the change in surface energy, when a mercury drop of radius $r$ splits up into 1000 droplets of radius $r$?

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A
$36pr^2t$
💡 Explanation:

Let bigger drop has radius $R$

Volume will remain same. 
 $\dfrac{4}{3}\pi R^3 = 1000\times \dfrac{4}{3} \pi r^3  \implies   r= \dfrac{R}{10}$

Change in surface energy-
 $A _2T - A _1T = 1000\times 4\pi r^2T-4\pi R^2T=4\pi[10R^2-R^2]T=36\pi R^2T$

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