The frequency of a light wave in a material is 2 $$ \times $$ 10¹⁴ Hz and wavelength is 5000 $$\mathop A\limits^ \circ $$. The refractive index of material will be

The angular resolution of a 10 cm diameter telescope at a wavelength of 5000 $$\mathop A\limits^ \circ $$ is of the order of

A telescope has an objective lens of 10 cm diameter and is situated at a distance of one kilometer from two objects. The minimum distance between these two objects, which can be resolved by the telescope, when the mean wavelength of light is 5000 $$\mathop A\limits^ \circ $$, is of the order of

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 ?