\(1~\text g\) of water of volume \(1~\text{cm}^3\) at \(100^\circ \text{C}\) is converted into steam at the same temperature under normal atmospheric pressure \(\approx 1\times10^{5}~\text{Pa}.\) The volume of steam formed equals \(1671~\text{cm}^3.\) If the specific latent heat of vaporization of water is \(2256~\text{J/g},\) the change in internal energy is:
1. \(2423~\text J\)
2. \(2089~\text J\)
3. \(167~\text J\)
4. \(2256~\text J\)
Consider a cycle followed by an engine (figure).
1 to 2 is isothermal,
2 to 3 is adiabatic,
3 to 1 is adiabatic.
Such a process does not exist, because:
(a) | heat is completely converted to mechanical energy in such a process, which is not possible. |
(b) | In this process, mechanical energy is completely converted to heat, which is not possible. |
(c) | curves representing two adiabatic processes don’t intersect. |
(d) | curves representing an adiabatic process and an isothermal process don't intersect. |
Choose the correct alternatives:
1. | (a), (b) | 2. | (a), (c) |
3. | (b), (c) | 4. | (c), (d) |
The figure below shows two paths that may be taken by gas to go from state \(A\) to state \(C.\)
In process \(AB,\) \(400~\text{J}\) of heat is added to the system, and in process \(BC,\) \(100~\text{J}\) of heat is added to the system. The heat absorbed by the system in the process \(AC\) will be:
1. \(380~\text{J}\)
2. \(500~\text{J}\)
3. \(460~\text{J}\)
4. \(300~\text{J}\)
The degree of freedom per molecule for a gas on average is 8. If the gas performs 100 J of work when it expands under constant pressure, then the amount of heat absorbed by the gas is:
1. 500 J
2. 600 J
3. 20 J
4. 400 J
An ideal gas goes from state \(A\) to state \(B\) via three different processes, as indicated in the \(P\text-V\) diagram. If \(Q_1,Q_2,Q_3\) indicates the heat absorbed by the gas along the three processes and \(\Delta U_1, \Delta U_2, \Delta U_3\) indicates the change in internal energy along the three processes respectively, then:
1. | \({Q}_1>{Q}_2>{Q}_3 \) and \(\Delta {U}_1=\Delta {U}_2=\Delta {U}_3\) |
2. | \({Q}_3>{Q}_2>{Q}_1\) and \(\Delta {U}_1=\Delta {U}_2=\Delta {U}_3\) |
3. | \({Q}_1={Q}_2={Q}_3\) and \(\Delta {U}_1>\Delta {U}_2>\Delta {U}_3\) |
4. | \({Q}_3>{Q}_2>{Q}_1\) and \(\Delta {U}_1>\Delta {U}_2>\Delta {U}_3\) |
1. | \(10~\text{J}\) | 2. | \(12~\text{J}\) |
3. | \(36~\text{J}\) | 4. | \(6~\text{J}\) |
A sample of \(0.1\) g of water at \(100^{\circ}\mathrm{C}\) and normal pressure (\(1.013 \times10^5\) N m–2) requires \(54\) cal of heat energy to convert it into steam at \(100^{\circ}\mathrm{C}\). If the volume of the steam produced is \(167.1\) cc, then the change in internal energy of the sample will be:
1. \(104.3\) J
2. \(208.7\) J
3. \(42.2\) J
4. \(84.5\) J
1 kg of gas does 20 kJ of work and receives 16 kJ of heat when it is expanded between two states. The second kind of expansion can be found between the same initial and final states, which requires a heat input of 9 kJ. The work done by the gas in the second expansion will be:
1. | 32 kJ | 2. | 5 kJ |
3. | -4 kJ | 4. | 13 kJ |