• # question_answer There is an air bubble of radius r inside a drop of water of radius 3R. Find the ratio of gauge pressure at point B to that of at point A. A)  $\frac{1}{2}$                       B)  $\frac{1}{4}$C)  $\frac{1}{3}$                       D)  $1$

As, pressure difference, ${{P}_{B}}-{{P}_{O}}=\frac{2T}{3R}$                      ?..(i) and       ${{P}_{A}}={{P}_{B}}+\frac{2T}{R}$                 ??(ii) From equations (i) and (ii), we get             ${{P}_{A}}-{{P}_{O}}=\frac{2T}{3R}+\frac{2T}{R}=2T\left[ \frac{4}{3R} \right]$ $\Rightarrow$               $\frac{{{P}_{B}}-{{P}_{O}}}{{{P}_{A}}-{{P}_{O}}}=\frac{1}{4}$