Question

A piece of blue glass heated to a high temperature and a piece of red glass at room temperature, are taken inside a room that is dimly lit, then ___________

(a) The blue piece will look blue and red will look as usual

(b) Red looks brighter and blue looks ordinary blue

(c) Blue shines like brighter red compared to the red pieces

(d) Both the pieces will look equally red

The question was asked in an international level competition.

This is a very interesting question from Thermal Expansion in portion Thermal Properties of Matter of Engineering Physics I

Answer 1

The correct option is (c) Blue shines like brighter red compared to the red pieces

To elaborate: According to Stefan’s law, E is proportional to T^4

As the temperature of blue glass is more than that of red glass, so it will appear brighter than red glass.