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. | \(380~\mathrm{K}\) |
The pressure of a monoatomic gas increases linearly from N/m2 to N/m2 when its volume increases from 0.2 m3 to 0.5 m3. The work done by the gas is:
1.
2.
3.
4.
1. | \(1000~\text{J}\) | 2. | zero |
3. | \(-2000~\text{J}\) | 4. | \(2000~\text{J}\) |
A thermodynamic system undergoes a cyclic process \(ABCDA\) as shown in Fig. The work done by the system in the cycle is:
1. \( P_0 V_0 \)
2. \( 2 P_0 V_0 \)
3. \( \frac{P_0 V_0}{2} \)
4. zero
In the P-V diagram shown, the gas does 5 J of work in the isothermal process ab and 4 J in the adiabatic process bc. What will be the change in internal energy of the gas in the straight path from c to a?
1. 9J
2. 1 J
3. 4 J
4. 5 J
\(ABCA\) is a cyclic process. Its \(P\text-V\) graph would be:
1. | ![]() |
2. | ![]() |
3. | ![]() |
4. | ![]() |
The volume (\(V\)) of a monatomic gas varies with its temperature (\(T\)), as shown in the graph. The ratio of work done by the gas to the heat absorbed by it when it undergoes a change from state \(\mathrm{A}\) to state \(\mathrm{B}\) will be:
1. | \(2 \over 5\) | 2. | \(2 \over 3\) |
3. | \(1 \over 3\) | 4. | \(2 \over 7\) |
A sample of \(0.1\) g of water at \(100^{\circ}\mathrm{C}\) and normal pressure (\(1.013 \times10^5\) N m–2) requires \(54\) cal of heat energy to convert it into steam at \(100^{\circ}\mathrm{C}\). If the volume of the steam produced is \(167.1\) cc,
then the change in internal energy of the sample will be:
1. \(104.3\) J
2. \(208.7\) J
3. \(42.2\) J
4. \(84.5\) J
The degree of freedom per molecule for a gas on average is 8. If the gas performs 100 J of work when it expands under constant pressure, then the amount of heat absorbed by the gas is:
1. 500 J
2. 600 J
3. 20 J
4. 400 J
In the following figures, four curves A, B, C and D, are shown. The curves are:
1. | isothermal for A and D while adiabatic for B and C. |
2. | adiabatic for A and C while isothermal for B and D. |
3. | isothermal for A and B while adiabatic for C and D. |
4. | isothermal for A and C while adiabatic for B and D. |