The figure shows the (P-V) diagram of an ideal gas undergoing a change of state from A to B. Four different paths I, II, III and 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 IV and III but not in cases I and II. |
(b) | The change in internal energy is the same in all four cases. |
(c) | Work done is maximum in case I. |
(d) | Work done is minimum in case II. |
Which of the following options contains only correct statements?
1. | (b), (c), (d) | 2. | (a), (d) |
3. | (b), (c) | 4. | (a), (c), (d) |
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 pressure and volume of a gas are changed as shown in the P-V diagram. The temperature of the gas will:
1. | increase as it goes from A to B. |
2. | increase as it goes from B to C. |
3. | remain constant during these changes. |
4. | decrease as it goes from D to A. |
Two cylinders contain the same amount of an ideal monoatomic gas. The same amount of heat is given to two cylinders. If the temperature rise in cylinder A is T0, then the temperature rise in cylinder B will be:
1.
2.
3.
4.
The incorrect relation is:
(where symbols have their usual meanings)
1.
2.
3.
4.
We consider a thermodynamic system. If ∆U represents the increase in its internal energy and W the work done by the system, which of the following statements is true?
1. | \(\Delta \mathrm{U}=-\mathrm{W}\) in an isothermal process |
2. | \(\Delta \mathrm{U}=\mathrm{W}\) in an isothermal process |
3. | \(\Delta \mathrm{U}=-\mathrm{W}\) in an adiabatic process |
4. | \(\Delta \mathrm{U}=\mathrm{W}\) in an adiabatic process |
Two cylinders, A and B, of equal capacity are connected to each other via a stopcock. A contains gas at a standard temperature and pressure. B is completely evacuated. The entire system is thermally insulated. If the stopcock is suddenly opened, then the change in internal energy of the gas is:
1. | 0
|
2. | 5 J
|
3. | 1 J
|
4. | 3 J |
Find out the total heat given to diatomic gas in the process ABC : (BC is isothermal)
1.
2.
3.
4. 3
0.04 mole of an ideal monatomic gas is allowed to expand adiabatically so that its temperature changes from 800 K to 500 K. The work done during expansion is nearly equal to:
1. | \(129.6\) J | 2. | \(-129.6\) J |
3. | \(149.6\) J | 4. | \(-149.6\) J |
If an ideal gas undergoes two processes at constant volumes as shown in the pressure-temperature (P-T) diagram, then:
1. =
2. >
3. <
4.