Railway lines are lend with gaps to allow for expansion.  If the gap between steel rails 66 m long be 3.63 cm at 10^o C, then the temperature at which the lines just touch will be :
(Given :

An electric fan is switched on in a closed room.  The air in the room

The average kinetic energy of a gas molecule at 27^o C is 6.21 x 10^-21 J.  Its average kinetic energy at 227^o C will be

If an oxygen atom and hydrogen atom are having the same temperature, then ratio of their average kinetic energy is

A piston of cross-section area A is fitted in cylinder in which gas of volume V at pressure P is enclosed.  Gas obeys Boyle's law, the angular frequency if piston is displaced slightly, is :

A given amount of gas at 20^o C has a pressure P.  The temperature at which the pressure will be 2 P (at constant volume) is approximately

A cylinder contains 10 kg of gas at a pressure of 10⁷ N/m² .  The quantity taken out of the cylinder if the final pressure is
.  (temperature of gas is constant) is