Properties Of Solids And Liquids Question 307
Question: The surface tension of soap solution is $ 25\times {{10}^{-3}}N{{m}^{-1}} $ .The excess pressure inside a soap bubble of diameter 1 cm is[AIIMS 1987]
Options:
A) 10 Pa
B) 20 Pa
C) 5 Pa
D)None of the above
Show Answer
Answer:
Correct Answer: B
Solution:
Excess pressure $ \Delta P=\frac{4T}{r} $
$ =\frac{4\times 2\times 25\times {{10}^{-3}}}{1\times {{10}^{-2}}} $
$ =20\ N/m^{2}=20\ Pa $
$ \left[ \text{as }r=\frac{d}{2} \right] $
