A light ray enters from medium A to medium B as shown in Figure 10.2. The refractive index of mediumB relative to A will be

fig 10.2.jpg

(a) greater than unity

(b) less than unity

(c) equal to unity

(d) zero

 

Answer

Relative refractive index = N 2 /N 1   

In this case, Relative refractive index, ղ = N b /N a

  • Going from Medium A to B, light ray bends towards the normal
  • When an incident ray passes from rarer to denser medium , it bends toward the normal.
  • Hence, Medium B is denser than Medium A
  • So, we can say that N b > N a .
  • Thus, Relative refractive index, ղ = N b /N a > 1

 

So, the correct answer is (a)

  1. Class 10
  2. Chapter 10 Class 10 - Light - Reflection and Refraction (Term 1)

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CA Maninder Singh
CA Maninder Singh is a Chartered Accountant for the past 11 years and a teacher from the past 11 years. He teaches Science, Accounts and English at Teachoo