The equation of state for 5 g of oxygen at a pressure P and temperature T, when occupying a volume V, will be
(where R is the gas constant)

An ideal gas heat engine operates in a Carnot cycle between 227^oC and 127^oC. It absorbs 6 kcal at the height temperature. The amount of heat (in kcal) converted into work is equal to

The efficiency of Carnot engine is 50% and temperature of sink is 500 K. If temperature of source is kept constant and its efficiency raised to 60%, then the required temperature of sink will be

A scientist says that the efficiency of his heat engine which work at source temperature 127^oC and sink temperature 27^oC is 26%, then