The $P-V$ diagram of a system undergoing thermodynamic transformation is shown in figure. The work done on the system in going from $A → B → C$ is $50 J$ and $ 20\, cal$ heat is given to the system. The change in internal energy between $A$ and $C$ is …… $J$

A diatomic gas, having $C_{p}=\frac{7}{2} R$ and $C _{ v }=\frac{5}{2} R ,$ is heated at constant pressure. The ratio $dU : dQ : dW :$

$Assertion :$ The heat supplied to a system is always equal to the increase in its internal energy.
$Reason :$ When a system changes from one thermal equilibrium to another, some heat is absorbed by it.

What is the total work done in a cyclic process ?

Three moles of an ideal monoatomic gas perform a cycle as shown in the figure. The gas temperature in different states are: $T_1 = 400\, K, T_2 = 800\, K, T_3 = 2400\,K$ and $T_4 = 1200\,K.$ The work done by the gas during the cycle is …….. $kJ$