Question

A light travels through water in the beaker. The height of water column is 'h'. Refractive index of water is 'μ_w'. If c is velocity of light in air, the time taken by light to travel through water will ______.

Options

• `"h"/(mu_"w""c")`

• `"hc"/(mu_"w")`

• `"h"mu_"w""c"`

• `(mu_"w""h")/"c"`

Answer 1

A light travels through water in the beaker. The height of water column is 'h'. Refractive index of water is 'μ_w'. If c is velocity of light in air, the time taken by light to travel through water will `underline((mu_"w""h")/"c")`.

Explanation:

`"Velocity" = "distance"/"time"`

`therefore "time" = "distance"/"Velocity" = "h"/"c" mu_"w"`

`therefore mu_"w" = "c"/"v"`

`therefore "v" = "c"/mu_"w"`