Question

Calculate the heat absorbed by a system in going through the cyclic process shown in figure.

Answer 1

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">π × 10⁴ × 10⁻⁶ × 10³ J

= 3.14 × 10 = 31.4 J