When an unpolarised light beam passes through a double refracting medium, it splits up into two beams called ordinary ray and extraordinary ray.Which of the following statements are correct?a)Intensity of both the rays remains constant.b)Refractive index of the ordinary ray remains constant.c)Refractive index of the extraordinary ray does not remain constant.d)Both the rays are unpolarised.Correct answer is option 'B,C'. Can you explain this answer?

Question

Answer

Introduction:
When an unpolarized light beam passes through a double refracting medium, it undergoes a phenomenon known as double refraction or birefringence. This phenomenon occurs due to the different refractive indices of the medium for different polarization directions of light. As a result, the incident beam splits into two beams called the ordinary ray and the extraordinary ray.

Explanation:
Let's analyze each statement and determine if it is correct or not:

a) Intensity of both the rays remains constant:
This statement is incorrect. When an unpolarized light beam passes through a double refracting medium, the ordinary and extraordinary rays have different intensities. The intensity of the ordinary ray remains constant, while the intensity of the extraordinary ray depends on the angle of incidence and the polarization of the incident light.

b) Refractive index of the ordinary ray remains constant:
This statement is correct. The ordinary ray behaves as if it is passing through a single refracting medium with a constant refractive index. The refractive index of the ordinary ray is independent of the angle of incidence and the polarization of the incident light.

c) Refractive index of the extraordinary ray does not remain constant:
This statement is correct. The refractive index of the extraordinary ray depends on the angle of incidence and the polarization of the incident light. It varies with the direction of the electric field vector of the incident light relative to the crystal structure of the double refracting medium.

d) Both the rays are unpolarized:
This statement is incorrect. When an unpolarized light beam passes through a double refracting medium, the ordinary and extraordinary rays are polarized. The ordinary ray remains polarized parallel to the direction of the incident electric field vector, while the extraordinary ray is polarized perpendicular to both the direction of the incident electric field vector and the direction of propagation.

Summary:
In summary, the correct statements are 'b) Refractive index of the ordinary ray remains constant' and 'c) Refractive index of the extraordinary ray does not remain constant'. The intensity of both rays is not constant, and both rays are polarized.

Top Courses for Physics

Suggested Free Tests

Related Content

Schools

Competitive Examinations

Quick Access Links

Technical Exams