When we heat an iron bar, it first becomes red, then yellow and finally begins to glow with white light and then blue light. Why ?

When we heat an iron bar, it first becomes red, then yellow and finall

1.	When we heat an iron bar, it first becomes red, then yellow and finally begins to glow with white light and then blue light. Why ?
Answer» SOLUTION :The change in colour is due to increase in the frequency of radiation emitted on heating as RED colour LIES in the lower frequency REGION while BLUE colour lies in the high frequency region.