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.	\(380~\mathrm{K}\)

One mole of an ideal gas expands at a constant temperature of 300 K from an initial volume of 10 litres to a final volume of 20 litres. The work done in expanding the gas is equal to:
(R = 8.31 J/mole-K)

1. 750 joules

2. 1728 joules

3. 1500 joules

4. 3456 joules

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. $1.8\times {10}^2 \mathrm{J}$

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 monoatomic gas at a pressure \(P\), having a volume \(V\), expands isothermally to a volume \(2V\) and then adiabatically to a volume \(16V\). The final pressure of the gas is: \(\left(\text{Take:}~ \gamma = \frac{5}{3} \right)\)

A horizontal cylinder has two sections of unequal cross-sections in which two pistons, A and B, can move freely. The pistons are joined by a string. Some gas is trapped between the pistons. If this gas is heated, the pistons will:  
         

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 efficiency of an ideal heat engine (Carnot heat engine) working between the freezing point and boiling point of water is:
1. \(26.8\%\)
2. \(20\%\)
3. \(6.25\%\)
4. \(12.5\%\)