Question

If surface tension of water is $7.3\times {10}^{-2}N/m.$ The excess pressure inside a spherical drop of radius $1mm$ is ........ $N/m^2$

• A. $146$
• B. $1.46$
• C. $14.6$
• D. $292$

Answer 1

Answer: (A)

$146$

Excess pressure for a drop = $\frac{2T}{R}$
= $\frac{2\times 7.3\times {10}^{-2}}{1\times {10}^{-3}}$

$=146N/m^2$
Hence, excess pressure inside a spherical drop is $146N/m^2$

Option A is correct.