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. \(300~\text{J}\)

Subtopic:  First Law of Thermodynamics |
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From NCERT
NEET - 2015
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A system is taken from state \(\text{a}\) to state \(\text{c}\) by two paths \(\text {adc}\) and \(\text {abc}\) as shown in the figure. The internal energy at \(\text a\) is \(\mathrm{U}_{\mathrm{a}}=10 \mathrm{~J}\). Along the path \( \text {adc}\) the amount of heat absorbed \(\delta Q_1=50 \mathrm{~J}\) and the work obtained \(\delta W_1=20 \mathrm{~J}\) whereas along the path \(\text {abc}\) the heat absorbed \(\delta Q_2=36 \mathrm{~J}\). The amount of work along the path \(\text {abc}\) is: 
      
1. \(10\) 2. \(12\)
3. \(36\) 4. \(6\) J
Subtopic:  First Law of Thermodynamics |
 81%
From NCERT
NEET - 2013
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An ideal gas goes from state \(A\) to state \(B\) via three different processes as indicated in the \((P\text-V)\) diagram.

  
If \(Q_1,Q_2,Q_3\) indicate the heat absorbed by the gas along the three processes and \(\Delta U_1, \Delta U_2, \Delta U_3\) indicate the change in internal energy along the three processes respectively, then:

1. \(Q_3>Q_2>Q_1\) and \(\Delta U_1= \Delta U_2= \Delta U_3\)
2. \(Q_1=Q_2=Q_3\) and \(\Delta U_1> \Delta U_2> \Delta U_3\)
3. \(Q_3>Q_2>Q_1\) and \(\Delta U_1> \Delta U_2> \Delta U_3\)
4. \(Q_1>Q_2>Q_3\) and \(\Delta U_1= \Delta U_2= \Delta U_3\)
Subtopic:  First Law of Thermodynamics |
 79%
From NCERT
AIPMT - 2012
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During an isothermal expansion, a confined ideal gas does -150 J of work against its surrounding. This implies that:

1. 300 J of heat has been added to the gas.
2. no heat is transferred because the process is isothermal.
3. 150 J of heat has been added to the gas.
4. 150 J of heat has been removed from the gas.

Subtopic:  First Law of Thermodynamics |
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From NCERT
AIPMT - 2011
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If \(\Delta U\) and \(\Delta W\) represent the increase in internal energy and work done by the system respectively in a thermodynamical process, which of the following is true?

1. \(\Delta U=-\Delta W\), in an adiabatic process
2. \(\Delta U=\Delta W\) , in an isothermal process
3. \(\Delta U=\Delta W\),  in an adiabatic process
4.  \(\Delta U=-\Delta W\), in an isothermal process
Subtopic:  First Law of Thermodynamics |
 81%
From NCERT
AIPMT - 2010
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The internal energy change in a system that has absorbed \(2\) kcal of heat and done \(500\) J of work is:
1. \(8900\) J
2. \(6400\) J
3. \(5400\) J
4. \(7900\) J

Subtopic:  First Law of Thermodynamics |
 77%
From NCERT
AIPMT - 2009
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