Properties Of Solids And Liquids Question 334
Question: The amount of work done in blowing a soap bubble such that its diameter increases from d to D is (T= surface tension of the solution) [MP PMT 1996]
Options:
A) $ 4\pi (D^{2}-d^{2})T $
B) $ 8\pi (D^{2}-d^{2})T $
C) $ \pi (D^{2}-d^{2})T $
D)$ 2\pi (D^{2}-d^{2})T $
Show Answer
Answer:
Correct Answer: D
Solution:
$ W=T\times 8\pi (r _{2}^{2}-r _{1}^{2})=T\times 8\pi \left( \frac{D^{2}}{4}-\frac{d^{2}}{4} \right) $
$ =2\pi (D^{2}-d^{2})T $
