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

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?

The pressure of a monoatomic gas increases linearly from $4\times {10}^5$ N/m² to $8\times {10}^5$ N/m² when its volume increases from 0.2 m³ to 0.5 m³. The work done by the gas is:

1. $2.8\times {10}^5 \mathrm{J}$

2. $1.8\times {10}^6 \mathrm{J}$

3. $1.8\times {10}^5 \mathrm{J}$

4. $1.8\times {10}^2 \mathrm{J}$

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:
           

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

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-V graph would be:

1.		2.
3.		4.

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: