Question

A cyan color light passed through a blue filter. What is color of light which comes out through the filter:
\[A.\] Green
\[B.\] Cyan
\[C.\] Yellow
\[D.\] Blue

Answer 1

Hint: - In this question we will use the concept of different types of filters, how it functions when light rays fall on it and the idea of color subtraction when light falls on any filter some of components of light are absorbed while some are reflected and some transmitted.

Formula used:
We will use the arithmetic equation for subtraction of color components of given color light.
\[C = B + G\]
Where \[C\]is cyan color light, \[B\]is blue color light and \[G\]is green color light.

Step by step solution:
A blue filter is a transparent material which allows only blue light passed through it and rest of the components of light get absorbed by it when a white light shine on it
In the same manner if cyan color light which is the mixture of blue and green light when passes through blue filters it absorbs the green light and transmits the blue light only.
Mathematically
When cyan color light falls on blue filter it subtracts the green color light and we will have only blue color transmitted \[T\]
     \[\]
\[T = C - G = (B + G) - G = B\]
Hence option \[(D)\] is correct.

Note: In this type of question we should have knowledge of filter functioning and composition of colors of different light such as white light, cyan color light, magenta etc. We should use the equations for color subtraction using the composition of different color light.