$200\,g$ of water is heated from $40\,^{\circ}C$ to $60\,^{\circ}C$. Ignoring the slight expansion of water,the change in its internal energy is close to ...... $kJ$ (Given specific heat of water $= 4184\,J/kg\cdot K$)

Is $P\Delta V$ an extensive or intensive variable?

The volume of a gas at a constant pressure of $50\,N/m^2$ changes from $10\,m^3$ to $4\,m^3$. If $100\,J$ of heat is supplied to the gas,the increase in internal energy is ....... $J$.

$A$ given quantity of gas is taken from $A$ to $C$ in two ways: $a$) directly from $A \rightarrow C$ along a straight line,and $b$) in two steps,from $A \rightarrow B$ and then from $B \rightarrow C$. The work done and heat absorbed along the direct path $A \rightarrow C$ are $200 \ J$ and $280 \ J$ respectively. If the work done along the path $A \rightarrow B \rightarrow C$ is $80 \ J$,find the heat absorbed along this path.

$A$ thermodynamic system absorbs $2 \, kcal$ of heat and performs $500 \, J$ of work. The change in its internal energy is ......... $J$.

$A$ system is provided with $200 \, cal$ of heat and the work done by the system on the surroundings is $40 \, J$. Then its internal energy