Three processes form a thermodynamic cycle as shown on the $P-V$ diagram for an ideal gas. Process $1 \rightarrow 2$ takes place at a constant temperature $(300 \ K)$. Process $2 \rightarrow 3$ takes place at a constant volume. During this process,$40 \ J$ of heat leaves the system. Process $3 \rightarrow 1$ is adiabatic and the temperature $T_3$ is $275 \ K$. The work done by the gas during the process $3 \rightarrow 1$ is ..... $J$.

The figure shows a cylindrical adiabatic container of total volume $2V_0$ divided into two equal parts by a conducting piston (which is free to move). Each part contains an identical gas at pressure $P_0$. Initially,the temperature of the left and right parts is $4T_0$ and $T_0$ respectively. An external force is applied on the piston to keep it at rest. Find the value of the external force required when thermal equilibrium is reached. ($A =$ Area of the piston)

Consider that an ideal gas ($n$ moles) is expanding in a process given by $P = f(V)$,which passes through a point $(V_0, P_0)$. Show that the gas is absorbing heat at $(P_0, V_0)$ if the slope of the curve $P = f(V)$ is larger than the slope of the adiabatic curve passing through $(P_0, V_0)$.

Is the splitting of water an exothermic or an endothermic process?

One mole of an ideal diatomic gas expands from volume $V$ to $2V$ isothermally at a temperature $27^{\circ} C$ and does $W$ joule of work. If the gas undergoes the same magnitude of expansion adiabatically from $27^{\circ} C$ doing the same amount of work $W$, then its final temperature will be (close to) . . . . . . ${ }^{\circ} C$.

The efficiency of a heat engine is $\eta$ and the coefficient of performance of a refrigerator is $\beta$. Then: