Question

A spherical black body with a radius of 12 cm radiates 450 watt power at 500 K.

Answer 1

Power radiated by black body is proportional to Area and Temp raised to power 4,

P =  σA(T^4)       ,Stefan-Boltzmann Law

Radius is halved area becomes one fourth Temp become doubled.

P becomes 4 times.

Power becomes 1800 W

Answer 2

All objects emit electromagnetic radiation according to their temperature. A black body is an idealized object that absorbs all electromagnetic radiation