Q. Three objects coloured black, gray and white can with stand hostile conditions at 2800$℃$. These objects are thrown into furnace where each of them attains a temperature of 2000$℃.$ Which object will glow brightest?
A) The white object
B) The black object
C) All glow with equal brightness
D) Gray object
Explanation
(b) An ideal black body absorbs all the radiations incident upon it and has an emissivity equal to 1. If a black body and an identical another body are kept the same temperature, then the black body will radiate maximum power.
Hence, the black object at a temperature of 2000$℃$ will glow brightest.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.