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MHT CET 2020 (16 Oct, Shift 1) · Splitting & Merging of Drops

Splitting & Merging of Drops question from MHT CET 2020 (16 Oct, Shift 1)

Q50MHT CET 2020 · 16 OCT · SHIFT 1Medium

Splitting & Merging of Drops

Two small drops of mercury each of radius rr coalesce to form a large single drop. The ratio of the total surface energies before and after the change is

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Answer: (b)

  1. R=21/3rR = 2^{1/3} r (volume conserved).
  2. EbeforeEafter=2⋅4πr2T4π22/3r2T=21/3\frac{E_{before}}{E_{after}} = \frac{2 \cdot 4\pi r^2 T}{4\pi 2^{2/3} r^2 T} = 2^{1/3}
  3. So the answer is (b) 21/3:12^{1/3} : 1.
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