Question

A spherical soap bubble of radius 3 cm is formed inside another spherical soap bubble of radius 6 cm. If the internal pressure of the smaller bubble of radius 3 cm in the above system is equal to the internal pressure of the another single soap bubble of radius r cm. The value of r is ___

Answer 1

The correct answer is 2
$\frac{4T}{R_1}+\frac{4T}{R_2} = \frac{4T}{r}$
$⇒ \frac{1}{r} = \frac{1}{3}+\frac{1}{6}$
$⇒ r = 2\ cm$
Therefore , the value of r is 2cm