PGLAW 2014 Panjab University Entrance Exam With Answers

The correct answer is A: Does not reflect any color.


A blackboard looks black because it does not reflect any color. Instead, it absorbs most of the light that strikes it. When light strikes an object, some of it is absorbed, and some of it is reflected. The color that we see is determined by the wavelengths of light that are reflected back to our eyes. In the case of a blackboard, very little light is reflected back, and what little is reflected is absorbed by the dark pigment in the chalk. This gives the board its characteristic black color.