Question

Work done in splitting a drop of water of 1 mm radius into 10 droplets is (surface tension of water $ =72\,\times {{10}^{-3}}J/{{m}^{2}} $ )

• A. $ 9.58\,\times {{10}^{-5}}J $
• B. $ 8.95\,\times {{10}^{-5}}J $
• C. $ 5.89\,\times {{10}^{-5}}J $
• D. $ 5.98\,\times {{10}^{-6}}J $

Answer 1

Answer: (B)

Work done in splitting a water drop of radius $ R $ into $ n $ drops of equal size $ =4\pi {{R}^{2}}T({{n}^{1/3}}-1) $ $ =4\pi \times {{({{10}^{-3}})}^{2}}\times 72\times {{10}^{-3}}\times ({{10}^{6/3}}-1) $ $ =4\pi \times {{10}^{-6}}\times 72\times {{10}^{-3}}\times 99 $ $ =8.95\times {{10}^{-5}}J $