NEET Physics Mechanical Properties of Fluids Questions Solved

$$\begin{gathered} \mathrm{Two} \mathrm{spherical} \mathrm{soap} \mathrm{bubbles} \mathrm{of} \mathrm{radii} {\mathrm{r}}_1 \mathrm{and} {\mathrm{r}}_2 \mathrm{in} \mathrm{vaccum} \mathrm{collapse} \mathrm{under} \mathrm{isothermal} \mathrm{condition}. \mathrm{The} \mathrm{resulting} \mathrm{bubble} \mathrm{has} \\ \mathrm{radius} \mathrm{equal} \mathrm{to}: \end{gathered}$$

1.  $\frac{{\mathrm{r}}_1 + {\mathrm{r}}_2}{2}$

2.  $\frac{{\mathrm{r}}_1{\mathrm{r}}_2}{{\mathrm{r}}_1 - {\mathrm{r}}_2}$

3.  $\sqrt{{\mathrm{r}}_1{\mathrm{r}}_1}$

4.  $\sqrt{{\mathrm{r}}_1^2 + {\mathrm{r}}_2^2}$