$A$ gas is compressed at a constant pressure of $50 \,N/m^2$ from a volume of $10 \,m^3$ to a volume of $4 \,m^3$. Energy of $100 \,J$ is then added to the gas by heating. Its internal energy is

Density of water at $4 ^\circ C$ and $20 ^\circ C$ are $1000 \ kg/m^3$ and $998 \ kg/m^3$ respectively. The increase in internal energy of $4 \ kg$ water when it is heated from $4 ^\circ C$ to $20 ^\circ C$ is . . . . . . $J$. (Specific heat capacity of water $= 4.2 \ kJ/kg \cdot K$ and $1$ atmospheric pressure $= 10^5 \ Pa$)

In a thermodynamic process,the pressure of a fixed mass of a gas is changed in such a manner that the gas releases $30 \,J$ of heat and $10 \,J$ of work is done on the gas. If the initial internal energy of the gas was $10 \,J$,then the final internal energy will be: (in $\,J$)

$A$ system is given $300$ calories of heat and it does $600$ joules of work. How much does the internal energy of the system change in this process? $(1 \text{ calorie} = 4.18 \text{ joules})$

Which of the following statements is incorrect regarding the first law of thermodynamics?

In a thermodynamic process,the pressure of a fixed mass of a gas is changed in such a manner that the gas releases $20 \ J$ of heat and $8 \ J$ of work is done on the gas. If the initial internal energy of the gas was $30 \ J$,the final internal energy will be ...... $J$.