question_answer

The frequency of a light wave in a material is \[2\times {{10}^{14}}\,Hz\] and wavelength is \[5000\text{ }{\AA}\]. The refractive index of material will be: [AIPMT (S) 2007]

A) 1.40

B)                   1.50                

C) 3.00     

D)                   1.33

Correct Answer: C

Solution :

Velocity of light waves in material is

....(i)

Refractive index of material is

(ii)

where c is speed of light in vacuum or air.

or                                              ...(iii)

Given,

Hence, from Eq. (iii), we get