Let and be the changes in internal energy of an ideal gas system in the processes A and B as shown in the figure, then (P: pressure, V: Volume)

1. >
2. =
3. <
3.
When heat \(Q\) is supplied to a diatomic gas of rigid molecules, at constant volume its temperature increases by \(\Delta T\). the heat required to produce the same change in temperature, at a constant pressure is:
1. \( \frac{7}{5} Q \)
2. \(\frac{3}{2} Q \)
3. \( \frac{2}{3} Q \)
4. \( \frac{5}{3} Q\)
| 1. | \(\dfrac{5}{3}\) | 2. | \(\dfrac{5}{2}\) |
| 3. | \(\dfrac{7}{5}\) | 4. | \(\dfrac{9}{7}\) |
| (i) | process \(AB\) – Isobaric expansion quadrupling the volume |
| (ii) | process \(BC\) – Isochoric cooling |
| (iii) | process \(CA\) – Adiabatic compression |

| 1. | For this gas, \(C_V=2R\) | 2. | \(C_P=3R\) |
| 3. | \(\gamma=\dfrac32\) | 4. | All the above are true |
A diatomic gas, having \(C_P=\dfrac{7}{2}R\) and \(C_V=\dfrac{5}{2}R\) is heated at constant pressure. The ratio of \(dU:dQ:dW\) is:
1. \(5:7:3\)
2. \(5:7:2\)
3. \(3:7:2\)
4. \(3:5:2\)
| 1. | \(50^{\circ}\text{C}\) | 2. | \(42^{\circ}\text{C}\) |
| 3. | \(61^{\circ}\text{C}\) | 4. | \(75^{\circ}\text{C}\) |
n moles of an ideal gas is heated at constant pressure
from 50°C to 100°C, the increase in internal energy
of the gas is
1.
2.
3.
4.
| 1. | \(\dfrac{n_1T_1+n_2T_2}{n_1+n_2}\) | 2. | \(\dfrac{n_1T_2+n_2T_1}{n_1+n_2}\) |
| 3. | \(\dfrac{n_1T_1-n_2T_2}{n_1-n_2}\) | 4. | \(\dfrac{n_1T_2-n_2T_1}{n_1-T_2}\) |