Show by drawing ray diagrams how a totally reflecting glass prism can be used to deviate a ray of light through (i) `90^(@)` (ii) `180^(@)` and invert it.

In periscopes, totally reflecting prisms are used which turns the ray through

Draw a ray diagram to show a right angled isosceles prism may be used to ''bend the path of light rays by 90^(@) . Write the necessary condition in terms of the refractive index of the material of this prism for the ray to bend to 90^(@) .

(a) Deduce the expression, by drawing a suitable ray diagram, for the refractive index of a triangular glass prisms in terms of the angle of minimum deviation (D) and the angle of prism (A). Draw a plot showing the variation of the angle of deviation with the angle of incidence. (b) Calculate the value of the angle of incidence when a ray of light incident on one face of an equilateral glass prism produces the emergent ray, which just grazes along the adjacent face. Refractive index of prism is sqrt2

Draw diagrams to show polarised and unpolarised light are represented in a ray diagram.

Draw a labelled ray diagram to show how a ray of light passes through a parallel sided glass block: a) if it hits the glass block at 90^(@) (that is perpendicular to the glass block).