Question

If you keep red coloured marbles in a blue coloured vase made of glass then the colour of red marbles will appear
A.Blue
B.Red
C.Black
D.White

Answer 1

Hint: It depends on the absorption and emission of light. The glass will absorb the radiation except the colour of glass.

Complete answer:
If the light is made to fall on the blue vase which is made up of glass then the vase will absorb all the colours of light except its own colour that is blue. So the light passing through the vase will only contain the blue light. Now in the vase the red marbles are places, when the light which has blue radiation will fall on the red marble, the red marble will absorb the blue radiation. Hence the emitted radiation will be black only because all the radiations are absorbed. Our eyes see the colour which is emitted and not the one which is absorbed. Hence the red marbles placed in a blue vase made of glass will seem as black in colour.

Hence, the correct option is C.

Note:
The optical spectrum we detect is a product of three colours that is cyan, magenta, and yellow. If we will look at a red or yellow object through a cyan lens, we will see black colour. But here is some exception; blue has more yellow in it than cyan. So looking at a blue object through yellow we will see green instead of black. In the spectrum blue and red are close to each other hence when placed together we will see them as black. This effect is more pronounced when coloured objects are illuminated only by certain colours of light. A green apple illuminated under only red light appears to us as black.