Question

An object that appears black under white light will appear _________ under blue light.

a. red

b. blue

c. green

d. purple

e. black

Answer 1

The answer is option e. black.

The phenomenon in which we see different colours is because of absorption and reflection of various wavelengths of the light in the visible spectrum. We know that a white light comprises of 7 different colours mixed together . Whenever this white light falls over any object then the object absorbs all the other wavelengths except for one wavelength which gets reflected from that object. This reflected wavelength gives a characteristic colour to any object.

A black object is an object which absorbs all the colours and reflect none. So whenever white light or any monochromatic light falls on a black object , no colour is reflected back.

So even if u incident a white light on a black object or a blue light it will absorb all of it and reflect none and hence will appear black no matter what light is incident on it.