Question:
The absolute refractive indices of glass and water are 4/3 and 3/2 respectively. If the speed of light in glass is 2*10 to the power 8 m/s, calculate the speed of light in (i) vacuum and (ii) water.
Answer:
The absolute refractive indices of glass = 4/3
The absolute refractive indices of water = 3/2
We know,
Absolute Refractive Indices of a medium = Speed of light in vacuum/Speed of light in medium
if, Speed of light in glass = 2 x 108 m/s
(i) Therefore,
or, Speed of light in vacuum = Absolute Refractive Indices of a medium X Speed of light in air
or, Speed of Light in vacuum = (3/2) x 2 x 108 m/s = 3 x 108 m/s
(ii )
Absolute Refractive Indices of a medium = Speed of light in vacuum/Speed of light in medium
Speed of Light in water = Speed of light in vaccum / Absolute Refractive Indices of water
or, Speed of light in water = 3 x 108 m/s / (4/3)
= 9/4 x 108 m/s
= 2.25 x 108 m/s
Not what you are looking for? Go ahead and submit the question, we will get back to you.
