A monoatomic gas at pressure P1 and volume V1 is compressed adiabatically to 1/8th its original volume. What is the final pressure of the gas?
1. P1
2. 16 P1
3. 32 P1
4. 64 P1
At a pressure of \(2\) atmospheres, a mass of diatomic gas \((\gamma = 1.4)\), is compressed adiabatically, causing its temperature to rise from \(27^{\circ}\mathrm{C}\) to \(927^{\circ}\mathrm{C}\). The pressure of the gas in the final state is:
1. 8 atm
2. 28 atm
3. 68.7 atm
4. 256 atm
An ideal gas goes from state \(A\) to state \(B\) via three different processes as indicated in the \((P\text-V)\) diagram.
If \(Q_1,Q_2,Q_3\) indicate the heat absorbed by the gas along the three processes and \(\Delta U_1, \Delta U_2, \Delta U_3\) indicate the change in internal energy along the three processes respectively, then:
1. | \(Q_3>Q_2>Q_1\) and \(\Delta U_1= \Delta U_2= \Delta U_3\) |
2. | \(Q_1=Q_2=Q_3\) and \(\Delta U_1> \Delta U_2> \Delta U_3\) |
3. | \(Q_3>Q_2>Q_1\) and \(\Delta U_1> \Delta U_2> \Delta U_3\) |
4. | \(Q_1>Q_2>Q_3\) and \(\Delta U_1= \Delta U_2= \Delta U_3\) |
1. | \(10~\text{J}\) | 2. | \(12~\text{J}\) |
3. | \(36~\text{J}\) | 4. | \(6~\text{J}\) |
The molar specific heat at a constant pressure of an ideal gas is \(\dfrac{7}{2}R.\) The ratio of specific heat at constant pressure to that at constant volume is:
1. | \(\dfrac{7}{5}\) | 2. | \(\dfrac{8}{7}\) |
3. | \(\dfrac{5}{7}\) | 4. | \(\dfrac{9}{7}\) |
A Carnot engine whose sink is at \(300~\mathrm{K}\) has an efficiency of \(40\)%. By how much should the temperature of the source be increased to increase its efficiency by \(50\)% of its original efficiency?
1. | \(275~\mathrm{K}\) | 2. | \(325~\mathrm{K}\) |
3. | \(250~\mathrm{K}\) | 4. | \(380~\mathrm{K}\) |
If \(Q\), \(E\), and \(W\) denote respectively the heat added, the change in internal energy, and the work done in a closed cycle process, then:
1. | \(W=0\) | 2. | \(Q=W=0\) |
3. | \(E=0\) | 4. | \(Q=0\) |
In thermodynamic processes which of the following statements is not true?
1. | In an adiabatic process, the system is insulated from the surroundings. |
2. | In an isochoric process, pressure remains constant. |
3. | In an isothermal process, the temperature remains constant. |
4. | In an adiabatic process \(PV^\gamma=\mathrm{constant}.\) |
The internal energy change in a system that has absorbed \(2\) kcal of heat and done \(500\) J of work is:
1. \(8900\) J
2. \(6400\) J
3. \(5400\) J
4. \(7900\) J