Question

An infinitely long cylindrical water filament of radius $R$ is surrounded by air. Assume water and air to be static. The pressure outside the filament is $P_{out}$ and the pressure inside is $P_{in}$. If $\gamma$ is the surface tension of the water-air interface, then $P_{in} - P_{out}$ is:

• A. $\frac{2\gamma}{R}$
• B. 0
• C. $\frac{\gamma}{R}$
• D. $\frac{4\gamma}{R}$

Answer 1

Answer: (C)

$\frac{\gamma}{R}$

Answer 2

The correct option is (C) :$\frac{\gamma}{R}$