Question

In a meniscus of radius $r$, with excess pressure $p$ in atmospheric pressure $p_0$, the force experienced

• A. $(p-p_0)\pi r^2$
• B. $(p-p_0)2\pi r$
• C. $p\pi r^2$
• D. $p_{0}2\pi r$

Answer 1

The correct option is C $p\pi r^2$

Difference in pressure between the inner and outer surface is $(p_i-p_0)$.
$\therefore Force=(p_i-p_0)\pi r^2$
Since excess pressure is given, $p=(p_i-p_0)$
$\therefore F=p\pi r^2$
So (c) is correct and the rest are incorrect.