A ray of light is incident normally on a glass slab of thickness 5cm and refractive index 1.6 . The time taken to travel by a ray from source to surface of the slab is the same as to travel through glass slab. The distance of the source from the surface is

Question

A ray of light is incident normally on a glass slab of thickness 5cm and refractive index 1.6 . The time taken to travel by a ray from source to surface of the slab is the same as to travel through glass slab. The distance of the source from the surface is (A) 4cm (B) 8cm (C) 12cm (D) 16cm

Tardigrade Admin · Accepted Answer

<img class="img-fluid question-image" alt="Solution" src="https://cdn.tardigrade.in/q/nta/p-hmnc7xlplqhs4vwm.jpg" /> Velocity of light in medium, v=(5/t) Velocity of light in vaccum, c = (x/t) μ = (c/v) = (x/5) x=5μ =8cm

Q. A ray of light is incident normally on a glass slab of thickness $5 c m$ and refractive index $1.6$ . The time taken to travel by a ray from source to surface of the slab is the same as to travel through glass slab. The distance of the source from the surface is

$4 c m$

$8 c m$

$12 c m$

$16 c m$

Velocity of light in medium, $v = \frac{5}{t}$

Velocity of light in vaccum, $c = \frac{x}{t}$
$μ = \frac{c}{v} = \frac{x}{5}$
$x = 5 μ = 8 c m$

Q. A ray of light is incident normally on a glass slab of thickness 5cm and refractive index 1.6 . The time taken to travel by a ray from source to surface of the slab is the same as to travel through glass slab. The distance of the source from the surface is

4cm

8cm

12cm

16cm