Check sibling questions

There are 2 main laws of Refraction of Light

 

Law 1

The Incident Ray,Refracted Ray and Normal Ray all lie on the same plane

 

Law 2

The Ratio of sin of Angle of Incidence and Angle of Refraction is constant for a particular medium

This constant is called Refractive Index

It is actually called Refractive Index of the second medium with respect to the first medium.

 

The second law of refraction is also called Snell's Law

 

Let's do some examples

Suppose for a ray of Light. Angle of Incidence = 37° and Angle of Refraction = 24°. Find Refractive Index
(Given: sin 37° = 0.6 and sin 24° = 0.4)

A beam of light passes from air into a substance X. If the angle of incidence be 72° and the angle of refraction be 40°, calculate the refraction index of substance X.
(Given: sin 72° = 0.951 and sin 40° = 0.642 )


Transcript

Example Suppose for a ray of Light. Angle of Incidence = 37° and Angle of Refraction = 24°. Find Refractive Index (Given: sin 37° = 0.6 and sin 24° = 0.4) We know that Refractive Index = (𝑠𝑖𝑛 (𝐴𝑛𝑔𝑙𝑒 𝑜𝑓 𝑖𝑛𝑐𝑖𝑑𝑒𝑛𝑐𝑒))/(𝑠𝑖𝑛 (𝐴𝑛𝑔𝑙𝑒 𝑜𝑓 𝑟𝑒𝑓𝑟𝑎𝑐𝑡𝑖𝑜𝑛)) Refractive Index = (𝑠𝑖𝑛 (37°))/(𝑠𝑖𝑛 (24°)) Refractive Index = 0.6/0.4 Refractive Index = 6/4 Refractive Index = 3/2 Refractive Index = 1.5 Example A beam of light passes from air into a substance X. If the angle of incidence be 72° and the angle of refraction be 40°, calculate the refraction index of substance X. (Given: sin 72° = 0.951 and sin 40° = 0.642 ) Given, Angle of incidence = ∠i = 72° Angle of Refraction = ∠r = 40° We have to find Refraction index of substance X By second law of refraction, Refractive index = sin⁡𝑖/sin⁡𝑟 = sin⁡〖72°〗/sin⁡〖40°〗 = 0.951/0.642 = 951/642 = 317/214 = 1.48 Refractive index of substance X is 1.48

  1. Class 10
  2. Chapter 10 Class 10 - Light - Reflection and Refraction

About the Author

Maninder Singh

CA Maninder Singh is a Chartered Accountant for the past 14 years and a teacher from the past 18 years. He teaches Science, Economics, Accounting and English at Teachoo