Which of the following statements is true/correct [Manipal MEE 1995

• A. During clear nights, the temperature rises steadily upward near the ground level
• B. Newton's law of cooling, an approximate form of Stefan's law, is valid only for natural convection
• C. The total energy emitted by a black body per unit time per unit area is proportional to the square of its temperature in the Kelvin scale
• D. Two spheres of the same material have radii \[1m\] and \[{{S}_{1}}\] and temperatures 4000 K and 2000 K respectively. The energy radiated per second by the first sphere is greater than that radiated per second by the second sphere