Question

Arrange descending order of reactive index of
water, air, glass and diamond
a) water greater than air greater than glass greater than diamond
b) water greater than glass greater than air greater than diamond
c) Diamond greater than glass greater than water greater than air
d) Diamond greater than water greater than glass greater than air

Answer 1

Answer:

$\bigstar\:\underline{\boxed{\bf{\red{Refractive\:Index:}}}}$

• Refractive index of a medium is defined as the factor by which speed of light reduces as compared to the speed of light in vacuum.
• More (less) refractive index implies less (more) speed of light in that medium, which therefore is called denser (rarer) medium.

$\bigstar\:\underline{\boxed{\bf{\blue{\mu=\dfrac{c}{v}=\dfrac{speed\:of\:light\:in\:vacuum}{speed\:of\:light\:in\:medium}}}}}$

✴ Practical Values :

፨ R.I. of water = 4/3 = 1.33

፨ R.I. of air = 1

፨ R.I. of glass = 3/2 = 1.5

፨ R.I. of diamond = 2.42

✴ Correct Descending order :

$\bigstar\:\underline{\boxed{\bf{\pink{Diamond>Glass>Water>Air}}}}\:\orange{\bigstar}$

Option-C ✔

Answer 2

Refractive Index :

• The ratio of the velocity of light in a vacuum to its velocity in a specified medium.

• $\bf \mu = \dfrac{c}{v}$

where ,

• μ refers to refractive index of the medium
• c refers to speed of the light in vacuum
• v refers to speed of light in medium

We know that ,

• Refractive Index of water = 4/3 = 1.34
• Refractive Index of air = 1
• Refractive Index of glass = 3/2 = 1.5
• Refractive Index of diamond = 2.42

So , Descending order of Refractive Indices are ,

Diamond > Glass > Water > Air

So , option C is correct .