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. \(12.5\%\)

A gas is compressed isothermally to half its initial volume. The same gas is compressed separately through an adiabatic process until its volume is again reduced to half. Then,

An ideal gas is compressed to half its initial volume using several processes. Which of the processes results in the maximum work done on the gas?
1. adiabatic
2. isobaric
3. isochoric
4. isothermal

The figure below shows two paths that may be taken by gas to go from state \(A\) to state \(C.\) 
                    
In process \(AB,\) \(400~\text{J}\) of heat is added to the system, and in process \(BC,\)  \(100~\text{J}\) of heat is added to the system. The heat absorbed by the system in the process \(AC\) will be:
1. \(380~\text{J}\)
2. \(500~\text{J}\)
3. \(460~\text{J}\)
4. \(300~\text{J}\)

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

A thermodynamic system is taken through the cycle \(ABCD\) as shown in the figure. Heat rejected by the gas during the cycle is: 
      

1. \(2 {PV}\)
2. \(4{PV}\)
3. \(\frac{1}{2}{PV}\)
4. \(PV\)