Solution 19D

Introduction

Here, here at first we have to see whether earth and sun system are in thermal equilibrium. Then we have to describe if there is any change in entropy in the heat process of heat transfer from sun to earth. Then we have to describe whether radiation, in terms of entropy change, is same or different.

Step 1

Two object are said to be in thermal equilibrium, if not heat is flowing from one object to another.

Now as we know that we receive energy from sun as the form of radiation. Hence we can say that the sun and earth are not in thermal equilibrium.