Question

An iron rod is heated. As it gets heated, it changes color. Which of the following colors indicates a very high temperature?

(a) Red

(b) Orange

(c) White

(d) Blue

I got this question during an interview.

I'd like to ask this question from Mechanism of Light Emission topic in division Optics of Engineering Physics II

Answer 1

Correct choice is (d) Blue

To explain I would say: As the body gets hotter, the frequency of the emitted radiation keeps on increasing. Blue color has the highest frequency out of red, orange and white. Thus, as the iron rod gets heated first it would become red, then orange, then white and then finally blue.