JEE Advanced 2017Paper 1
- Exam
- JEE Advanced
- Year
- 2017
- Paper
- Paper 1
- Subject
- Physics
- Chapter
- Mechanical Properties of Fluids
JEE Advanced 2017 · Paper 1 · Physics · Mechanical Properties of Fluids
A drop of liquid of radius R = 10 ^ - 2 m having surface tension S...
A drop of liquid of radius having surface tension divides itself into K identical drops. In the process the total change in the surface energy . If then the value of is
Correct answer
0
Step-by-step solution
By mass conservation, ρ . \dfrac{4}{3}π{R}^{3} = ρ . K . \dfrac{4}{3}π{r}^{3}
∴ ΔU = TΔA = T\left(K . 4π{r}^{2} - 4π{R}^{2}\right)
= T\left(K . 4π{R}^{2}{K}^{- \dfrac{2}{3}} - 4π{R}^{2}\right)
ΔU = 4π{R}^{2}T\left[{K}^{\dfrac{1}{3}} - 1\right]
Putting the value’s \to {10}^{- 3} = \dfrac{{10}^{- 1}}{4π} × 4π × {10}^{- 4}\left[{K}^{\dfrac{1}{3}} - 1\right]
\to {K}^{\dfrac{1}{3}} ≅ 100 = {10}^{2}
Given that K = {10}^{α} \to ∴ {10}^{\dfrac{α}{3}} = {10}^{2}
\to \dfrac{α}{3} = 2
\to α = 6