Question

Pressure inside two soap bubbles are $1.02atm$ and $1.05atm$ respectively. The ratio of their surface area is:

• A. $\frac{125}{8}$
• B. $\frac{25}{4}$
• C. $\frac{5}{2}$
• D. $\frac{2}{5}$

Answer 1

The correct option is B $\frac{25}{4}$

Excess pressure$\Delta P=\frac{4T}{R}$

$\frac{\Delta P_1}{\Delta P_2}=\frac{R_2}{R_1}=\frac{2}{5}$

$\frac{S_1}{S_2}=(\frac{R_2}{R_1}{)}^2=\frac{25}{4}$