A black body radiates energy at the rate E Wm^$$-$$2 at high temperature TK. When the temperature is reduced to $$\left( {{T \over 4}} \right)$$ K, the new radiant energy is

In an adiabatic process, where pressure is decreased by $${3 \over 4}$$%, if $${{{C_p}} \over {{C_v}}} = {4 \over 3}$$, then the volume increases by

A Carnot engine has the same efficiency between 600 K to 300 K and 1600 K to x K, then the value of x is

A vessel contains one mole of O₂ gas (molar mass 32) at a temperature T. The pressure of the gas is p. An identical vessel containing one mole of He gas (molar mass 4) at a temperature 2T has a pressure of