An ideal gas is taken from state $1$ to state $2$ through optional path $A, B, C \& D$ as shown in $P-V$ diagram. Let $Q, W$ and $U$ represent the heat supplied, work done $\&$ internal energy of the gas respectively. Then

The heat absorbed by a system in going through the given cyclic process is:

An ideal gas is made to undergo the cyclic process shown in the figure below. Let $\Delta W$ depict the work done, $\Delta U$ be the change in internal energy of the gas and $Q$ be the heat added to the gas. Sign of each of these three quantities for the whole cycle will be (0 refers to no change)

An enclosed ideal gas is taken through a cycle as shown in the figure. Then

The $P-V$ diagram of a system undergoing thermodynamic transformation is shown in figure. The work done by the system in going from $A \to B \to C$ is $30J$ and $40J$ heat is given to the system. The change in internal energy between $A$ and $C$ is ……. $J$