A glass slab of thickness `4 cm` contains the same number of waves as `5 cm` of water, when both are traversed by the same monochromatic light. If the refractive index of water is `4//3,` then refractive index of glass is

Options

A. `5//3`
B. `5//4`
C. `16//15`
D. 1.5

Answer

A

Explanation

Given that `""_(w)mu_(g)=(5)/(4) and ""_(a)mu_(w)(4)/(3)`
`therefore ""_(a)mu_(g)=""_(w)mu_(g)xx""_(a)mu_(w)=(5)/(4)xx(4)/(3)=(5)/(3)`