Two spherical soap bubbles of radii `r_1` and `r_2` in vacuume coalesce under isothermal condition. The resulting bubble has radius `R` such that

Options

A. `R=(r_(1)+r_(2))//2`
B. `R=r_(1)(r_(1)r_(2)+r_(2))`
C. `R^(2)=r_(1)^(2)+r_(2)^(2)`
D. `R=r_(1)+r_(2)`

Answer

C