When a beam of white light is passed through a prism, it splits to form lights of seven colours. Is it possible to recombine the lights of seven colours to obtain the white light again? Explain your answer.
Yes, it is possible to recombine the lights of seven colours to obtain the white light again, and this can be done by placing another similar prism alongside the first prism used but it should be in inverted position. The positions of both prisms are shown bellow,
When the beam of white light enters the prism 1 then it gets dispersed in to seven colors, the prism 2 which is kept alongside the prism 1 but in inverted direction receives the all seven colors then the prism 2 recombines the all colors to form a single white light. This is due to the refraction produced by the second prism is equal and opposite to that of the refraction produced by the first prism.