A gas at state A changes to state B through path I and II shown in figure. The changes in internal energy are ΔU₁ and ΔU₂ respectively. Then

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

The temperature of source and sink of a heat engine are 127^oC and 27^oC respectively. An inventor claims its efficiency to be 26%, then

Universal gas constant is

The internal energy change, when a system goes from state A to B is 40 kJ mole^-1. If the system goes from A to B by a reversible path and returns to state A by an irreversible path, what would be the net change in internal energy ?

P-V plots for two gases during adiabatic processes are shown in figure. Plots 1 and 2 should correspond respectively to 

                         

The internal energy change in a system that has absorbed 2 kcal of heat and done 500 J of work is

A mono atomic ideal gas, initially at temperature T₁ is enclosed in a cylinder fitted with a friction-less piston. The gas is allowed to expand adiabatically to a temperature T₂ by releasing the piston suddenly. L₁ and L₂ are the lengths of the gas column before and after expansion respectively, then T₁/T₂ is given by

A diatomic ideal gas is used in a Carnot engine as the working substance. If during the adiabatic expansion part of the cycle the volume of the gas increased from V to 32 V, the efficiency of the engine is

An ideal gas is taken through the cycle A B C A as shown in the figure. If the net heat supplied to the gas in the cycle is 5 J, the work done by the gas in the process C A is