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Question
Calculate the heat absorbed by a system in going through the cyclic process shown in figure.
Solution
Using the first law of thermodynamics, we get
ΔQ = ΔU + ΔW
Since internal energy depends only on the initial and final points and for a cyclic process, initial and final points are the same, change in internal energy of the system during this process will be zero.
⇒ ΔU = 0
⇒ ΔQ = ΔW
Heat absorbed = Work done
Work done = Area under the graph in the given case
Thus,
Heat absorbed = Area of the circle
Diameter of the circle = 300 - 100 = 200
Heat absorbed = π"> × 104 × 10−6 × 103 J
= 3.14 × 10 = 31.4 J
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