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MHT CET 2026 (15 May, Shift 2) · Splitting & Merging of Drops

Splitting & Merging of Drops question from MHT CET 2026 (15 May, Shift 2)

Q9MHT CET 2026 · 15 MAY · SHIFT 2Medium

Splitting & Merging of Drops

Two water drops each of radius rr coalesce to form a big drop. If TT is the surface tension, the surface energy released in this process is 4πr2Tx4\pi r^2 T x. The value of xx is

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Answer: (a)

  1. Volume conserved: R3=2r3⇒R=21/3rR^3 = 2r^3 \Rightarrow R = 2^{1/3} r.
  2. Energy released =T(2⋅4πr2−4π22/3r2)=4πr2T(2−22/3)= T\left(2 \cdot 4\pi r^2 - 4\pi 2^{2/3} r^2\right) = 4\pi r^2 T\left(2 - 2^{2/3}\right)
  3. So x=2−22/3x = 2 - 2^{2/3}, answer (a).
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