Three objects colored black, gray and white can withstand hostile conditions upto $2800\,^oC$. These objects are thrown into a furnace where each of them attains a temperature of $2000\,^oC$. Which object will glow brightest?
AIIMS 2006, Easy
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Black has greatest emissivity and greatest absorbtivity as compared with other colours. At $2000\,^oC$ it will have greatest emissivity so it will glow brightest.
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