Question

The excess of pressure inside a soap bubble than that of the outer pressure is

• A. $\frac{2T}{r}$
• B. $\frac{4T}{r}$
• C. $\frac{T}{2r}$
• D. $\frac{T}{r}$

Answer 1

The correct option is B $\frac{4T}{r}$

The pressure inside the bubble is more than outside. Inside pressure -outside pressure =excess pressure. In the case of bubble excess pressure = 4S/R. where s is the surface tension and r is the radius.

$△P=\frac{4T}{r}$