$A$ 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? $(J = 4.18 \text{ Joules/cal})$ (in joule)

$A$ thermodynamic system is changed from state $(P_1, V_1)$ to $(P_2, V_2)$ by two different processes. The quantity which will remain the same is

During the process $A \rightarrow B \rightarrow C$,the work done is $50 \, J$ and the heat supplied is $20 \, cal$. Find the change in internal energy between $A$ and $C$ in $J$. (in $, J$)

When a system is taken from state $i$ to a state $f$ along path $iaf$,$Q = 50 \, J$ and $W = 20 \, J$. Along path $ibf$,$Q = 35 \, J$. If $W = -13 \, J$ for the curved return path $fi$,$Q$ for this path is ...... $J$.

An electric heater supplies heat to a system at a rate of $100\;W.$ If the system performs work at a rate of $75\;J/s,$ at what rate (in $J/s$) is the internal energy increasing?

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 $30 \ J$,then the final internal energy will be ........ $J$.