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

A monoatomic ideal gas, initially at temperature T₁ is enclosed in a cylinder fitted with a frictionless piston. The gas is allowed to expand adiabatically to a temperature T₂ by releasing the piston suddenly. If l₁ and l₂ are the lengths of the gas column, before and after the expansion respectively, then the value of $${{{T_1}} \over {{T_2}}}$$ will be :