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JEE Main 2022 (28 Jun, Shift 1) · Splitting & Merging of Drops

Splitting & Merging of Drops question from JEE Main 2022 (28 Jun, Shift 1)

Q44JEE Main 2022 · 28 JUN · SHIFT 1Medium

Splitting & Merging of Drops

A water drop of diameter 2 cm is broken into 64 equal droplets. The surface tension of water is 0.075 N/m. In this process the gain in surface energy will be:

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Answer: (a)

  1. Use ΔE=4πR2T(n1/3−1)\Delta E = 4\pi R^2 T\left(n^{1/3} - 1\right) with R=1 cm=0.01 mR = 1\text{ cm} = 0.01\text{ m}.
  2. n=64⇒n1/3=4n = 64 \Rightarrow n^{1/3} = 4
  3. ΔE=4π(10−4)(0.075)(3)=2.83×10−4 J\Delta E = 4\pi (10^{-4})(0.075)(3) = 2.83 \times 10^{-4}\text{ J}
  4. So the answer is (a) 2.8×10−4 J2.8 \times 10^{-4}\text{ J}.
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