Select Chapter Topics:
Q. No.An ideal gas undergoes a cyclic process \(ABCDA\) as shown in given \(P\text-V\) diagram given below. The amount of work done by the gas is:
1. \(6 P_0 V_0\)
2. \(-2 P_0 V_0 \)
3. \(+2 P_0 V_0 \)
4. \(+4 P_0 V_0\)
Subtopic: Work Done by a Gas |
85%
Level 1: 80%+
Please attempt this question first.
Hints
Please attempt this question first.
Consider two containers A and B containing identical gases at the same pressure, volume and temperature. The gas in container A is compressed to half of its original volume isothermally while the gas in container B is compressed to half of its original value adiabatically. The ratio of final pressure of gas in B to that of gas in A is
1. \(2^{\gamma-1} \)
2. \(\left(\frac{1}{2}\right)^{\gamma-1} \)
3. \(\left(\frac{1}{1-\gamma}\right)^2 \)
4. \(\left(\frac{1}{\gamma-1}\right)^2\)
1. \(2^{\gamma-1} \)
2. \(\left(\frac{1}{2}\right)^{\gamma-1} \)
3. \(\left(\frac{1}{1-\gamma}\right)^2 \)
4. \(\left(\frac{1}{\gamma-1}\right)^2\)
Subtopic: Types of Processes |
71%
Level 2: 60%+
Please attempt this question first.
Hints
Consider a heat engine as shown in Fig. 12.7. \(Q_1\) and \(Q_2\) are heat added to heat bath \(T_1\) and heat taken from \(T_2\) in one cycle of engine. W is the mechanical work done on the engine.
If W > 0, then possibilities are:
1. \( Q _1> Q _2>0 \)
2. \( Q _2> Q _1>0 \)
3. \( Q _2< Q _1<0 \)
4. \(G _1<0, B _2>0\)
Choose the correct option:
1. (a), (d)
2. (b), (c), (d)
3. (a), (b), (c)
4. (a), (c)
If W > 0, then possibilities are:
1. \( Q _1> Q _2>0 \)
2. \( Q _2> Q _1>0 \)
3. \( Q _2< Q _1<0 \)
4. \(G _1<0, B _2>0\)
Choose the correct option:
1. (a), (d)
2. (b), (c), (d)
3. (a), (b), (c)
4. (a), (c)
Level 3: 35%-60%
Please attempt this question first.
Hints
Mark the correct options:
Choose the correct option:
1. (a), (d)
2. (b), (c), (d)
3. (a), (b), (c)
4. (b), (d)
| a. | A system X is in thermal equilibrium with Y but not with Z. System Y and Z may be in thermal equilibrium with each other. |
| b. | A system X is in thermal equilibrium with Y but not with Z. Systems Y and Z are not in thermal equilibrium with each other. |
| c. | A system X is neither in thermal equilibrium with Y nor with Z. The systems Y and Z must be in thermal equilibrium with each other. |
| d. | A system X is neither in thermal equilibrium with Y nor with Z. The system Y and Z may be in thermal equilibrium with each other |
1. (a), (d)
2. (b), (c), (d)
3. (a), (b), (c)
4. (b), (d)
Subtopic: Basic Terms |
74%
Level 2: 60%+
Please attempt this question first.
Hints
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) |
Subtopic: First Law of Thermodynamics | Second Law of Thermodynamics |
57%
Level 3: 35%-60%
Hints
The figure shows the \((P\text-V)\) diagram of an ideal gas undergoing a change of state from \(A\) to \(B.\) Four different paths \(\mathrm{I, II, III}\) and \(\mathrm{IV},\) as shown in the figure, may lead to the same change of state.
| (a) | The change in internal energy is the same in cases \(\mathrm{IV}\) and \(\mathrm{III}\) but not in cases \(\mathrm{I}\) and \(\mathrm{II}.\) |
| (b) | The change in internal energy is the same in all four cases. |
| (c) | The work done is maximum in case \(\mathrm{I}.\) |
| (d) | The work done is minimum in case \(\mathrm{II}.\) |
Which of the following options contains only correct statements?
| 1. | (b), (c) and (d) only | 2. | (a) and (d) only |
| 3. | (b) and (c) only | 4. | (a), (c) and (d) only |
Subtopic: Work Done by a Gas |
81%
Level 1: 80%+
Hints
An ideal gas undergoes an isothermal process from some initial state \(i\) to the final state \(𝑓\).
Choose the correct alternatives:
| (a) | \(dU = 0 \) | (b) | \(dQ = 0\) |
| (c) | \(dQ = dU \) | (d) | \(dQ = dW\) |
| 1. | (a), (b), (c) | 2. | (a), (d) |
| 3. | (b), (c), (d) | 4. | (a), (c), (d) |
Subtopic: First Law of Thermodynamics |
86%
Level 1: 80%+
Hints
Which of the processes described below are irreversible?
Choose the correct alternative/s:
| (a) | The increase in temperature of an iron rod by hammering it. |
| (b) | A gas in a small container at a temperature \(T_1\) is brought in contact with a big reservoir at a higher temperature \(T_2\) which increases the temperature of the gas. |
| (c) | A quasi-static isothermal expansion of an ideal gas in a cylinder fitted with a frictionless piston. |
| (d) | An ideal gas is enclosed in a piston-cylinder arrangement with adiabatic walls. A weight \(w\) is added to the piston, resulting in the compression of gas. |
| 1. | (a), (b), (c) | 2. | (a), (d) |
| 3. | (b), (c), (d) | 4. | (a), (b), (d) |
Subtopic: Types of Processes |
Level 3: 35%-60%
Hints
Three copper blocks of masses \(M_{1} , M_{2} \) and \(M_{3}~\text{kg}\) respectively are brought into thermal contact till they reach equilibrium. Before contact, they were at \(T_{1} , T_{2} , T_{3} \left(\right. T_{1} > T_{2} > T_{3} \left.\right).\) Assuming there is no heat loss to the surroundings, the equilibrium temperature \(T\) is:
(\(s\) is the specific heat of copper)
(\(s\) is the specific heat of copper)
| 1. | \(T = \dfrac{T_{1} + T_{2} + T_{3}}{3}\) |
| 2. | \(T = \dfrac{M_{1} T_{1} + M_{2} T_{2} + M_{3} T_{3}}{M_{1} + M_{2} + M_{3}}\) |
| 3. | \(T = \dfrac{M_{1} T_{1} + M_{2} T_{2} + M_{3} T_{3}}{3 \left(\right. M_{1} + M_{2} + M_{3} \left.\right)}\) |
| 4. | \(T = \dfrac{M_{1} T_{1} s + M_{2} T_{2} s + M_{3} T_{3} s}{M_{1} + M_{2} + M_{3}}\) |
Subtopic: First Law of Thermodynamics |
71%
Level 2: 60%+
Hints
Consider the \((P\text-V)\) diagram for an ideal gas shown in the figure.
Out of the following diagrams, which figure represents the \((T\text-P)\) diagram?
| 1. |  |
2. |  |
| 3. |  |
4. |  |
Subtopic: Types of Processes |
59%
Level 3: 35%-60%
Hints
Select Chapter Topics:
© 2025 GoodEd Technologies Pvt. Ltd.