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JEE Main20241 Feb 2024Evening ShiftPhysicsMechanical Properties of FluidsActual

A big drop is formed by coalescing 1000 small droplets of water. The surface energy will become :

Options

  1. A100 times
  2. B10 times
  3. C1 100 th
  4. D1 10 th

Correct answer

D. 1 10 th

Step-by-step solution

Lets say radius of small droplets is r and that of big drop is R . Total volume of the drops will remains unchanged. Therefore, 4 3 π R 3 = 1000 4 3 π r 3 ⇒ R = 10 r Now, initial surface energy is, U i = 1000 4 π r 2 S and the final surface energy is, U f = 4 π R 2 S = 100 4 π r 2 S Clearly, U f = 1 10 U i .

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