A glass or plastic plate has thousands of closely drawn parallel lines on it. When unpolarized light is incident at 52 o onto a refletive surface, the reflected beam is polarized. The size of the image is then 6 cm. The image is 50 cm behind the mirror and is virtual, the same way up as the object and 6 cm high. Draw sketches to show how internal reflection is made use of in prisms to change the direction of a light beam through 90 and 180 o .
Dispersion is the splitting up of white light into the various colors of the visible spectrum.
It occurs because the refractive of materials is wavelength dependent. The refraction, and hence the deviation caused by a prism for example, is wavelength dependent. Blue light is deviated the most and red the least. Draw a sketch.