NTA Abhyas JEE Main2020PhysicsMechanical Properties of FluidsPractice
A liquid drop having surface energy E is spread into 512 droplets of same size. The final surface energy of the droplets is
Options
- A2 E
- B4 E
- C8 E
- D12 E
Correct answer
C. 8 E
Step-by-step solution
The surface area of the liquid drop is A = 4 πR 2 Its surface energy is E When the drop splits in 512 droplets, the surface area of each droplet is 4 πr 2 ∴ Total surface area A 2 = 512 × 4 πr 2 The volume of bigger drop is 4 3 πR 3 and volume of small droplets is 512 × 4 3 πr 3 ∴    4 3 πR 3 = 512 × 4 3 πr 3 ⇒ r = R 8 ∴    A 2 = 512 × 4 πr 2 = 512 × 4 π R 8 2 = 8 A 1 Surface energy E = A . T ( T is sur