How would the pattern on the screen change it?

Question

A beam of white light shines through a glass prism in a darkened room to produce the colors of white light. How would the pattern on the screen change it:

a. a pure red filter were placed in the path of the beam?

b. a pure blue screen were substituted for the white screen?

c. both the red filter and the blue screen were used?

--tsk.tsk.

Answer 1

a filter will remove all wavelengths other than its specific color, so only the red light will pass through the prism, and only the red light will hit the screen. the blue screen will only reflect blue light, absorbing all other frequencies and so the light coming off it will only be blue.

so

a: the light on the screen will be red, all other colors were absorbed

b: the only light observed on the screen will be blue.

c: as only red light reaches the screen there will be no light coming off the screen as it will be absorbed