The pressure and density of a diatomic gas changes adiabatically from (P, d) to (P', d'). If , then should be:
1. | 1/128 | 2. | 32 |
3. | 128 | 4. | None of the above |
Two identical samples of a gas are allowed to expand, (i) isothermally and (ii) adiabatically. The work done will be:
1. | more in the isothermal process. |
2. | more in the adiabatic process. |
3. | equal in both processes. |
4. | none of the above. |
In an adiabatic expansion of a gas, if the initial and final temperatures are \(T_1\) and \(T_2\), respectively, then the change in internal energy of the gas is:
1. \(\frac{nR}{\gamma-1}(T_2-T_1)\)
2. \(\frac{nR}{\gamma-1}(T_1-T_2)\)
3. \(nR ~(T_1-T_2)\)
4. Zero
One mole of an ideal gas at an initial temperature of T K does 6R joules of work adiabatically. If the ratio of specific heats of this gas at constant pressure and at constant volume is 5/3, the final temperature of the gas will be:
1. | (T + 2.4)K | 2. | (T – 2.4)K |
3. | (T + 4)K | 4. | (T – 4)K |
In a cyclic process, the internal energy of the gas:
1. | increases | 2. | decreases |
3. | remains constant | 4. | becomes zero |
In a Carnot engine, when \(T_2=0^\circ \mathrm{C}\) and \(T_1=200^\circ \mathrm{C},\) its efficiency is \(\eta_1\) and when \(T_1=0^\circ \mathrm{C}\) and \(T_2=-200^\circ \mathrm{C},\) its efficiency is \(\eta_2.\) What is the value of \(\frac{\eta_1}{\eta_2}?\)
1. | 0.577 | 2. | 0.733 |
3. | 0.638 | 4. | cannot be calculated |
When an ideal diatomic gas is heated at constant pressure, the fraction of the heat energy supplied which increases the internal energy of the gas is:
1. | \(\dfrac{2}{5}\) | 2. | \(\dfrac{3}{5}\) |
3. | \(\dfrac{3}{7}\) | 4. | \(\dfrac{5}{7}\) |
A closed hollow insulated cylinder is filled with gas at \(0^{\circ}\mathrm{C}\) and also contains an insulated piston of negligible weight and negligible thickness at the middle point. The gas on one side of the piston is heated to \(100^{\circ}\mathrm{C}\).
If the piston moves 5 cm, the length of the hollow cylinder will be:
1. 13.65 cm
2. 27.3 cm
3. 38.6 cm
4. 64.6 cm
A monoatomic gas is supplied with the heat \(Q\) very slowly, keeping the pressure constant. The work done by the gas will be:
1. \({2 \over 3}Q\)
2. \({3 \over 5}Q\)
3. \({2 \over 5}Q\)
4. \({1 \over 5}Q\)