badge image

Enroll For Free Now & Improve Your Performance.

User Icon
User Icon
User Icon
User Icon
User Icon

Thank you for registering.

One of our academic counsellors will contact you within 1 working day.

Please check your email for login details.

Use Coupon: CART20 and get 20% off on all online Study Material

Total Price: Rs.

There are no items in this cart.
Continue Shopping
Grade: 12


derive an expression for the refractive index of the material of a prism in terms of angle of minimum deviation and angle of prism

2 years ago

Answers : (1)

24742 Points
Dear Raza
The angle of deviation D = angle bent by emerging ray with respect to incident ray. D is the exterior angle of the triangle PP'Q'. It is sum of two interior angles.
See derivation in the diagram. 
A + Q +90 + 90 = 360 and Q+r1+r2 = 180  
So A = r1 + r2
D = (i-r1) + ( e-r2) = (i  + e) - (r1 +r2)
D = i + e - A
Vary i and then e varies. At one point D is minimum and at that point i = e.
When D is minimum and = Dm, we see that i = e and r1 = r2 = r
D = 2 i - A
i = (D+A)/2
r = A/2          as r1+r2 = 2 r  = A.
μ = sin i / sin r  = [ sin (A+Dm)/2 ]  / (  sin A/2 )
we can do an experimental setup to measure A, Dm and create the conditions for minimum deviation of incident light. We can calculate the refractive index for the material that the prism is made of.
Refractive index is not property of Prism. it is of the material.
2 years ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies

Course Features

  • 731 Video Lectures
  • Revision Notes
  • Previous Year Papers
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Test paper with Video Solution

Course Features

  • 70 Video Lectures
  • Revision Notes
  • Test paper with Video Solution
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Previous Year Exam Questions

Ask Experts

Have any Question? Ask Experts

Post Question

Answer ‘n’ Earn
Attractive Gift
To Win!!! Click Here for details