Diameter of human eye lens is 2 mm. What will be the minimum distance between two points to resolve them, which are situated at a distance of 50 meter from eye. The wavelength of light is 5000 $$\mathop A\limits^ \circ $$

For the given incident ray as shown in figure, the condition of total internal refraction of this ray the required refractive index of prism will be

A ray of light travelling in air have wavelength $$\lambda $$, frequency n, velocity v and intensity $$I$$. If this ray enters into water then these parameters are $$\lambda $$', n', v' and $$I$$' respectively. Which relation is correct from following ?

Optical fibre are based on