The work done in splitting a water drop of radius R into 64 droplets is ( $\mathrm{T}=$ surface tension of water)

Under isothermal conditions, two soap bubbles of radii $r_1$ and $r_2$ coalesce to form a big drop. The radius of the big drop is

When one end of the capillary is dipped in water, the height of water column is ' $h$ '. The upward force of 108 dyne due to surface tension is balanced by the force due to the weight of water column. The inner circumference of the capillary is (surface tension of water $=7.2 \times 10^{-2} \mathrm{~N} / \mathrm{m}$ )

A capillary tube when immersed vertically in water, the rise of water column is upto height $h_1$ on earth's surface. When this arrangement is taken into a mine of depth 'd', below earth's surface, the height of the water column is $\mathrm{h}_2$. If R is the radius of the earth, the ratio $\frac{\mathrm{h}_2}{\mathrm{~h}_1}$ is