Question

Two liquid drops have diameters of $1\, cm$ and $1.5\, cm$ The ratio of excess of pressures inside them is

• A. $1:1$
• B. $5:3$
• C. $2:3$
• D. $3:2$

Answer 1

Answer: (D)

$3:2$

Answer 2

Excess pressure inside a liquid drop
$\Delta p=\frac{2 T}{R}$
where $T$ is surface tension and $R$ is radius of liquid drop.
$=\frac{\Delta p_{1}}{\Delta p_{2}}=\frac{R_{2}}{R_{1}}$
$=\frac{0.75}{0.50}$
$\Rightarrow \frac{\Delta p_{1}}{\Delta p_{2}}=\frac{3}{2}$