A capillary glass tube records a rise of 20 cm when dipped in water. When the area of cross- section of the tube is reduced to half of the former value, water will rise to a height of:-

The root mean square speed of molecules of a gas is 1260 m/s. The average speed of the gas molecules is

A block rests on an inclined plane making an angle of 30° with the horizontal. The coefficient of static friction between block and the plane is 0.8. If the frictional force on the block is 10 N, then mass of block (in kg) (Take g = 10 m/s² )

In a container, 1 g of hydrogen and 1 g of oxygen are taken. Find the ratio of hydrogen pressure to oxygen pressure,

Find the temperature of H₂ gas at which its rms speed is equal to that of O₂ at 47°C.

In an isobaric process, the absolute temperature is doubled. The mean free path (l) and the  relaxation time (t) will become respectively