question_answer

The temperature of the surface of the sun is approximately\[\mathbf{6000}\text{ }\mathbf{K}\]. If we take a big lens and focus the sun rays, can we produce a temperature of\[\mathbf{8000}\text{ }\mathbf{K}\]?

Answer:

                No. According to second law of thermo- dynamics, heat by itself cannot flow from a body at lower temperature to a body at higher temperature. This can only be accomplished with the help of an external agency.