Question

What will be the diameter of a water droplet, the pressure inside which is 0.05 $N/c{m}^2$ greater than the outside pressure? (surface tension = 0.075 $N/m$)

• A. 3 mm
• B. 0.3 mm
• C. 0.6 mm
• D. 6 mm

Answer 1

The correct option is C 0.6 mm

$p=\frac{4\sigma }{d}$
$d$ - diameter of the droplet
$\sigma$ - surface tension
$p$ - pressure difference between the liquid
so, $d=\frac{4\sigma }{p}=6\times {10}^{-4}m=$0.6 mm