$Assertion :$ The isothermal curves intersect each other at a certain point.
$Reason :$ The isothermal changes takes place rapidly, so the isothermal curves have very little slope.

A monoatomic ideal gas, initially at temperature $T_1$, is enclosed in a cylinder fitted with a frictionless piston. The gas is allowed to expand adiabatically to a temperature $T_2$ by releasing the piston suddenly. If $L_1$ and $L_2$ are the lengths of the gas column before and after expansion respectively, then $T_1/T_2$ is given by

Helium gas goes through a cycle $ABCDA$ (consisting of two isochoric and two isobaric lines) as shown in figure. Efficiency of this cycle is nearly ….. $\%$ (Assume the gas to be close to ideal gas) 

Two cylinders of equal size are filled with equal amount of ideal diatomic gas at room temperature. Both the cylinders are fitted with pistons. In cylinder A the piston is free to move while in $B$ position is fixed. When same amount of heat is supplied to both the cylinders, the temperature of the gas cylinder $A$ raises by $30\, K$. What will be the rise in temperature of the gas in cylinder $B.$

Six moles of an ideal gas performs a cycle shown in figure. If the temperatures are $T_A = 600\, K,$ $T_B = 800\,K,$ $T_C = 2200\,K$ and $T_D = 1200\,K,$ then the work done per cycle is approximately …… $kJ$