Physics - Fluid Question with Solution | TestHub

In a cylinder-piston arrangement, air is under a pressure ${\mathrm{P}}_1$. A soap bubble of radius r lies inside the cylinder, soap bubble has surface tension T. The radius of soap bubble is to be reduced to half. The new pressure ${\mathrm{P}}_2$ to which air should be compressed isothermally is : (Assume r is very small as compared to height of cylinder)