A refrigerator works between 4^oC and 30^oC. It is required to remove 600 calories of heat every second in order to keep the temperature of the refrigerated space constant. The power required is (Take 1 cal = 4.2 Joules)

A gas is compressed isothermally to half its initial volume. The same gas is compressed separately through an adiabatic process until its volume is again reduced to half. Then

The molecules of a given mass of a gas have r.m.s. velocity of 2000 m s^$$-$$1 at 27^oC and 1.0 $$ \times $$ 10⁵ N m^$$-$$2 pressure. When the temperature and pressure of the gas are respectively, 127^oC and 0.05 $$ \times $$ 10⁵ N m^$$-$$2, the r.m.s. velocity of its molecules in m s^$$-$$1 is

Two vessels separately contain two ideal gases A and B at the same temperature, the pressure of A being twice that of B. Under such conditions, the density of A is found to be 1.5 times the density of B. The ratio of molecular weight of A and B is