Question

68. The first law of thermodynamics for isothermal process is
A) = W B) AU = W C) AU-9
lide
bu​

Answer 1

Answer:

When a system returns to its original state after completing a series of changes, then it is known that a cycle is completed. This process is known as cyclic process. In a cyclic process the initial and the final state is same. As the internal energy U of the system depends only on the state of the system so in a cyclic process the net change of internal energy, ∆U will be equal to zero i.e. ∆U = 0. Hence from the first law (∆U = Q+W)

Hence, W = – Q

Answer 2

Explanation:

According to the first law of thermodynamics

ΔU=q+W

For an isothermal process, ΔU=0

Hence,

q+W=0 or

q=−W