Question

A monochromatic light passes through a glass slab (refractive index=3/2) of thickness 90 cm in time t1. If it takes a time t2 to travel the same distance through water (refractive index=4/3).The value of (t1_ t2) is
1)5*10^_8s 2)5*10^_10s 3)2.5*10^_10s 4)2.5 *10^_8s

Answer 1

Answer: t₁-t₂=5×10⁻¹⁰s

Explanation:

The refractive index is given by:

μ=c/v

where c is the speed of light in vacuum and v is the speed of light in a medium.

we know that, time = distance / speed

It is given that refractive index of glass slab is, μ₁=3/2

v₁=c/μ₁=3×10⁸m/s/(3/2)=2.0×10⁸m/s

d=90 cm=0.90 m

t₁=d/v₁=0.90 m/(2.0×10⁸m/s)0

⇒t₁=0.45 ×10⁻⁸s

It is given that refractive index of water is, μ₂=4/3

v₂=c/μ₂=3×10⁸m/s/(4/3)=2.25×10⁸m/s

d=90 cm=0.90 m

t₂=d/v₂=0.90 m/(2.25×10⁸m/s)

⇒t₂=0.40 ×10⁻⁸s

t₁-t₂=0.45 ×10⁻⁸s-0.40 ×10⁻⁸s=0.05×10⁻⁸s=5×10⁻¹⁰s

Hence, the correct option is option 2)5×10⁻¹⁰s

Answer 2

Answer:

hope it helps you friend