Heat And Thermodynamics - Mechanics - Physics Previous Year Questions

One mole of \(\mathrm{O}_2\) gas is heated at constant pressure starting at \(27^{\circ} \mathrm{C}\). How much energy must be added to the gas as to double its volume?

A thermodynamic system undergoes a cyclic process \(A B C\) as shown in the diagram. The work done by the system per cycle is

A sphere, a cube and a thin circular plate all of same material and same mass initially heated to same high temperature are allowed to cool down under similar conditions. Then, the

In an adiabatic expansion of an ideal gas the product of pressure and volume

A certain amount of heat energy is supplied to a monoatomic ideal gas which expands at constant pressure. What fraction of the heat energy is converted into work?

A number of Carnot engines are operated at identical cold reservoir temperatures \((T_L)\). However, their hot reservoir temperatures are kept different. A graph of the efficiency of the engines versus hot reservoir temperature \((T_H)\) is plotted. The correct graphical representation is

Which of the following curves represent the variation of coefficient of volume expansion of an ideal gas at constant pressure?

A gas mixture contains monoatomic and diatomic molecules of 2 moles each. The mixture has a total internal energy of (symbols have usual meanings)

"Heat cannot be flow itself from a body at lower temperature to a body at higher temperature". This statement corresponds to

Pressure of ideal gas at constant volume is proportional to .........

\(100 \mathrm{~g}\) of ice at \(0^{\circ} \mathrm{C}\) is mixed with \(100 \mathrm{~g}\) of water at \(100^{\circ} \mathrm{C}\). The final temperature of the mixture is

[Take, \(L_f=3.36 \times 10^5 \mathrm{~J} \mathrm{~kg}^{-1}\) and \(S_w=4.2 \times 10^3 \mathrm{~J} \mathrm{~kg}^{-1} \mathrm{~K}^{-1} \text { ] }\)

The \(p\)-\(V\) diagram of a Carnot's engine is shown in the graph below. The engine uses 1 mole of an ideal gas as working substance. From the graph, the area enclosed by the \(p\)-\(V\) diagram is [The heat supplied to the gas is 8000 J]

The speed of sound in an ideal gas at a given temperature \(T\) is \(v\). The rms speed of gas molecules at that temperature is \(v_{\text {rms }}\). The ratio of the velocities \(v\) and \(v_{\text {rms }}\) for helium and oxygen gases are \(X\) and \(X^{\prime}\) respectively. Then, \(\frac{X}{X^{\prime}}\) is equal to

A solid cube of mass $m$ at a temperature $\theta_0$ is heated at a constant rate. It becomes liquid at temperature $\theta_1$ and vapour at temperature $\theta_2$. Let $s_1$ and $s_2$ be specific heats in its solid and liquid states respectively. If $L_f$ and $L_v$ are latent heats of fusion and vaporisation respectively, then the minimum heat energy supplied to the cube until it vaporises is