The temperature of the surface of the sun is approximately 6000 K. If we take a big lens and focus the sun rays, can we produce atemperatuer of 8000 K?

Explanation

No, According to second law of thermodynamics heat itself cannot be transferred from a cold body to a hot body i.e., the creation of temperature of 8000 K by transferring heat from a cold body at 6000 K is not possible by means of a lens. This is the violation of the second law of thermodynamics