Wavelength of given light waves in air and in a medium are 6000 Å and 4000 Å respectively the critical angle is

Options

A. `tan^(-1)((2)/(3))`
B. `tan^(-1)((3)/(2))`
C. `Sin^(-1)((2)/(3))`
D. `sin^(-1)((3)/(2))`

Answer

C

Explanation

Here `lambda_(air)`=6000Å ,`lambda_("medium")`=4000 Å
Let C be the critical angle.
`therefore sinC(1)/(air_(mu_(medium)))medium_(muair) =(mu_(air))/(mu_(medium))`
`SinC=(2)/(3)impliesCsin^(-1)((2)/(3))`