In: Physics
A beam of white light (400 – 700 nm) is shone at a small equilateral quartz prism. 1.5 m behind the prism is a large screen. What is observed on the screen, and where, if (A) the beam is incident on a vertex of the prism, and (B) if the beam is incident normal to one of the faces? Assume both the prism and the width of the beam are non-zero but negligible relative to the prism-screen distance. The index of refraction of quartz for 400 nm light is 1.47 and it is 1.45 for 700 nm light.
Please answer part B numerically, many answers are claiming the screen would show white light in part B. However, wouldn't the beam pass following the normal when entering, however diffract when exiting the prism?
There
is difference in refraction and diffraction, refraction occurs when
light passes from one medium to another and diffraction occurs when
light remains in the same medium but encounters an obstacle of the
size comparable to wavelength of the light. Part a of the problem
shows diffraction while part b of the problem shows refraction.
Hope you got the clarity in the two phenomenon, if there is any
doubt plz ask.