The number of molecules in one litre of an ideal gas at 300 K and 2 atmospheric pressure with mean kinetic energy 2 $$\times$$ 10^$$-$$9 J per molecules is :

In the reported figure, there is a cyclic process ABCDA on a sample of 1 mol of a diatomic gas. The temperature of the gas during the process A $$\to$$ B and C $$\to$$ D are T₁ and T₂ (T₁ > T₂) respectively.


Choose the correct option out of the following for work done if processes BC and DA are adiabatic.

A heat engine has an efficiency of $${1 \over 6}$$. When the temperature of sink is reduced by 62$$^\circ$$C, its efficiency get doubled. The temperature of the source is :

For a gas C_P $$-$$ C_V = R in a state P and C_P $$-$$ C_V = 1.10 R in a state Q, T_P and T_Q are the temperatures in two different states P and Q respectively. Then