Question 115 of 190
A sample of an ideal gas is taken through the cyclic process as shown in figure. It absorbs, of heat during the part , no heat during and rejects of heat during . A work of is done on the gas during the part . The internal energy of the gas at is . The work done by the gas during the part is
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Answer: (B)
In the part , the volume remains constant. Thus, the work done by the gas is zero. It is given that the heat absorbed by the gas is . From first law of thermodynamics,
or
The increase in internal energy from to is . The internal energy is at , then
In the part , the work done by the gas is and no heat is given to the system. Again using
or
The change in internal energy from ,
The heat given to the system is
Using , we get
or
The increase in internal energy from to is . The internal energy is at , then
In the part , the work done by the gas is and no heat is given to the system. Again using
or
The change in internal energy from ,
The heat given to the system is
Using , we get
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