A closed water tank has cross-sectional area $$A$$. It has a small hole at a depth of $$h$$ from the free surface of water. The radius of the hole is $$r$$ so that $$r \ll \sqrt{\frac{A}{\pi}}$$. If $$p_o$$ is the pressure inside the tank above water level and $$p_a$$ is the atmospheric pressure, the rate of flow of the water coming out of the hole is ( $$\rho$$ is density of water)

Two capillary tubes $$P$$ and $$Q$$ are dipped vertically in water. The height of water level in capillary tube $$P$$ is $$\frac{2}{3}$$ of the height in capillary tube $$Q$$. The ratio of their diameter is