The PV diagram of an ideal gas is shown in the figure. The work done by the gas in the process 1→2→3→4 is given by:

          

1. \(\frac{9}{2}P_0V_0\) 2. \(\frac{15}{2}P_0V_0\)
3. \(\frac{13}{2}P_0V_0\) 4. \(\frac{3}{2}P_0V_0\)

Subtopic:  Work Done by a Gas |
 55%
Level 3: 35%-60%
Hints

A pressure \((P)\) versus volume \((V)\) graph is obtained for an ideal gas from state \(A\) to state \(B\) (as shown in the figure below). Which of the following is the correct statement?
             

1. The temperature of gas increases continuously.
2. The temperature of gas decreases continuously.
3. The temperature first increases, then decreases.
4. The temperature first decreases, then increases.
Subtopic:  Types of Processes |
Level 3: 35%-60%
Hints

When the sink temperature is kept at \(400~\text{K},\) the efficiency of a Carnot engine is \(50\text{%}.\) While keeping the source temperature constant, by how much should we reduce the sink temperature to increase the efficiency to \(60\text{%}\text{?}\)

1. \(80\) K 2. \(70\) K
3. \(320\) K 4. \(240\) K
Subtopic:  Carnot Engine |
 66%
Level 2: 60%+
Hints

advertisementadvertisement

Which of the following graph shows the variation of pressure P with volume V for an ideal gas at a constant temperature?

1. 2.
3. 4.
Subtopic:  Types of Processes |
 85%
Level 1: 80%+
Hints

A gas performs the minimum work when it expands:

1. Isochorically 2. Isobarically
3. Adiabatically 4. Isothermally
Subtopic:  Types of Processes |
 75%
Level 2: 60%+
Hints

An ideal gas goes from \(A\) to \(B\) via two processes, \(\mathrm{I}\) and \(\mathrm{II},\) as shown. If \(\Delta U_1\) and \(\Delta U_2\) are the changes in internal energies in processes \(\mathrm{I}\) and \(\mathrm{II},\) respectively, (\(P:\) pressure, \(V:\) volume) then:

   

1. \(∆U_1 > ∆U_2\) 2. \(∆U_1 < ∆U_2\)
3. \(∆U_1 = ∆U_2\) 4. \(∆U_1 \leq ∆U_2\)
Subtopic:  Molar Specific Heat |
 89%
Level 1: 80%+
Hints

advertisementadvertisement

An ideal monoatomic gas \(\left(\gamma = \frac{5}{3}\right )\) absorbs 50 cal in an isochoric process. The increase in internal energy of the gas is:

1. 20 cal 2. Zero
3. 50 cal 4. 30 cal
Subtopic:  First Law of Thermodynamics |
 80%
Level 1: 80%+
Hints

The pressure-temperature \((P\text-T)\) graph for two processes, \(A\) and \(B,\) in a system is shown in the figure. If \(W_1\) and \(W_2\) are work done by the gas in process \(A\) and \(B\) respectively, then:

      

1. \(W_{1}=W_2\) 2. \(W_{1}<W_2\)
3. \(W_{1}>W_2\) 4. \(W_{1}= - W_2\)
Subtopic:  Work Done by a Gas |
 72%
Level 2: 60%+
Hints

The variation of molar heat capacity at constant volume CV with temperature T for a monatomic gas is:

1. 2.
3. 4.
Subtopic:  Molar Specific Heat |
 57%
Level 3: 35%-60%
Hints

advertisementadvertisement

When a system is moved from state \(a\) to state \(b\) along the path \(acb\), it is discovered that the system absorbs \(200~\text{J}\) of heat and performs \(80~\text{J}\) of work.  Along the path \(adb\), heat absorbed \(Q =144~\text{J}\). The work done along the path \(adb\) is:

   

1. \(6~\text{J}\) 2. \(12~\text{J}\)
3. \(18~\text{J}\) 4. \(24~\text{J}\)
Subtopic:  First Law of Thermodynamics |
 88%
Level 1: 80%+
Hints