Let '$$\mathrm{R_1}$$' and '$$\mathrm{R_2}$$' are radii of two mercury drops. A big mercury drop is formed from them under isothermal conditions. The radius of the resultant drop is

The force required to take away a flat circular plate of radius $$2 \mathrm{~cm}$$ from the surface of water is $$\left[\right.$$Surface tension of water $$\left.=70 \times 10^{-3} \mathrm{Nm}^{-1}, \pi=\frac{22}{7}\right]$$

Two spherical rain drops reach the surface of the earth with terminal velocities having ratio $16: 9$. The ratio of their surface area is

Water rises upto a height $h$ in a capillary tube on the surface of the earth. The value of $h$ will increase, if the experimental setup is kept in [ $g=$ acceleration due to gravity]