Physics Circle home Student Login

Home›Chapters›Surface Tension PYQs›Splitting & Merging of Drops›Question 20

JEE Main 2025 (24 Jan, Shift 1) · Splitting & Merging of Drops

Splitting & Merging of Drops question from JEE Main 2025 (24 Jan, Shift 1)

Q20JEE Main 2025 · 24 JAN · SHIFT 1Medium

Splitting & Merging of Drops

The amount of work done to break a big water drop of radius ' RR ' into 27 small drops of equal radius is 10 J. The work done required to break the same big drop into 64 small drops of equal radius will be

Show answer and solution

Answer: (d)

  1. W=4πR2T(n1/3−1)W = 4\pi R^2 T\left(n^{1/3} - 1\right), so W∝(n1/3−1)W \propto \left(n^{1/3} - 1\right) for the same drop.
  2. n=27n = 27: factor 3−1=23 - 1 = 2; n=64n = 64: factor 4−1=34 - 1 = 3.
  3. W′=10×32=15 JW' = 10 \times \frac{3}{2} = 15\text{ J}
  4. So the answer is (d) 15 J.
Report a mistake

More questions on Splitting & Merging of Drops