A planet radiates heat at a rate proportional to the fourth power of its surface temperature T . If such a steady temperature of the planet is due to an exactly equal amount of heat received from the sun then which of the following statement is true?

Rate of loss of energy by unit area of the planet  =σT4, Where σ  is a Stefan’s constant. Let  Q be the total energy emitted by the sun in every second. If d  is the distance of the planet from the sun, then Q  falls uniformly over the inner surface of the sphere of radius  d. Rate of gain of heat by unit area of planet =Q4πd2  For steady temperature of planetσT4=Q4πd2 T4=Q4πσd2 or T=(Q4πσd2)1/4 or T∝1d