WBJEE · Physics · Mechanical Properties of Fluids
27 drops of mercury coalesce to form a bigger drop. What is the relative increase in surface energy?
- A \(\frac{3}{2}\)
- B \(\frac{2}{3}\)
- C \(-\frac{2}{3}\)
- D 8
Answer & Solution
Correct Answer
(C) \(-\frac{2}{3}\)
Step-by-step Solution
Detailed explanation
Let the initial radius \(r\) and finial radius \(R . \frac{4}{3} \pi R^3=27 \times \frac{4}{3} \pi r^3 \Rightarrow R=3 r\) \[ U_i=\left(S 4 \pi r^2\right) \times 27 \quad U_f=S 4 \pi 9 r^2 \] Relative increacase…
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