$A$ process is shown in the diagram. Which of the following curves may represent the same process?

What are the differences between mechanics and thermodynamics?

$A$ thermodynamic system undergoes a cyclic process through four stages. The energy values involved during this process are $Q_1 = 600 \ J, Q_2 = -400 \ J, Q_3 = -300 \ J$,and $Q_4 = 200 \ J$. The work values are $W_1 = 300 \ J, W_2 = -200 \ J, W_3 = -150 \ J$,and $W_4$. Find the value of $W_4$ in $J$.

$A$ monoatomic ideal gas is heated at constant pressure. The percentage of total heat used in increasing the internal energy and that used for doing external work is $A$ and $B$ respectively. Then the ratio,$A: B$ is

If heat energy $\Delta Q$ is supplied to an ideal diatomic gas,the increase in internal energy is $\Delta U$ and the amount of work done by the gas is $\Delta W$. The ratio $\Delta W: \Delta U: \Delta Q$ is

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