A ray of light is incident on a glass slab of thickness t. Refractive index = 1.5 and the angle of refraction is 60°. Time taken by the ray to travel through the slab is (c = velocity of light in air)

Question

A ray of light is incident on a glass slab of thickness t. Refractive index = 1.5 and the angle of refraction is 60°. Time taken by the ray to travel through the slab is (c = velocity of light in air) (A) (3t/c)  (B) (3t/ 2 c)  (C) (2t/3c)  (D) (4t/3c)

Tardigrade Admin · Accepted Answer

Time taken by the ray to travel through the slab is T = (AC/v) = (AB / cos 60°/c / μ ) Here, AB = t , μ = 1.5 ∴ : T = (t / 0.5/c / 1.5) = (3t/c)

Q. A ray of light is incident on a glass slab of thickness t. Refractive index = 1.5 and the angle of refraction is $6 0^{\circ}$ . Time taken by the ray to travel through the slab is (c = velocity of light in air)

$\frac{3 t}{c}$

$\frac{3 t}{2 c}$

$\frac{2 t}{3 c}$

$\frac{4 t}{3 c}$

Time taken by the ray to travel through the slab is
$T = \frac{A C}{v} = \frac{A B / c o s 6 0 ^{\circ}}{c / μ}$
Here, $A B = t, μ = 1.5$
$∴ : T = \frac{t /0.5}{c /1.5} = \frac{3 t}{c}$

Q. A ray of light is incident on a glass slab of thickness t. Refractive index = 1.5 and the angle of refraction is 60∘. Time taken by the ray to travel through the slab is (c = velocity of light in air)

c3t​

2c3t​

3c2t​

3c4t​