A ray of light travelling in a transparent medium falls on a surface separating the medium from air, at an angle of incidence of `45^@`. The ray undergoes total interal reflection. If `mu` is the refractive index of the medium with respect to air, select the possible values of `mu` from the following:
(i) `1.3`
(ii) `1.4`
(iii) `1.5`
(iv) `1.6`

Options

A. (i), (ii)
B. (ii), (iii)
C. (iii), (iv)
D. (i), (iv)

Answer

C

Explanation

`sinC=1/mu`
`igtC` i.e. `45^@gtC`
`sin45^@gtsinCimplies1/sqrt2gt1/mu`
`mugtsqrt2` i.e. `mugt1.4`