>
>
Time management is very much important in IIT JAM. The eduncle test series for IIT JAM Mathematical Statistics helped me a lot in this portion. I am very thankful to the test series I bought from eduncle.
Nilanjan Bhowmick AIR 3, CSIR NET (Earth Science)
Shivam Sharma posted an Question
September 06, 2020 • 21:50 pm
![]()
30 points
30 points
- CSIR NET
- Earth Sciences
The optic axis interference figure of a hypothetical uniaxial mineral is shown below. the mineral has indices of refraction (r.is) of 1.54 and 1.55. the colors
The optic axis interference figure of a hypothetical uniaxial mineral is shown below. The mineral has indices of refraction (R.Is) of 1.54 and 1.55. The colors in the different quadrants of the interference figure reflect the effects of insertion of gypsum (Gyps) plate, the fast vibration direction of which marked in the figure. Yellow What is the optic sign of the mineral? State the value of the RI. of the mineral, corresponding to its E-ray (n). i) What is the value of the birefringence of the mineral in the optic orientation shown in the figure above? () (11)
2 Answer(s)
Answer Now
- 1 Likes
- 3 Comments
- 0 Shares
-
![comment-profile-img]()
>
-
![comment-profile-img]()
>
Rahul kumar Best Answer
1. Optic sign of the mineral is -ve (Uniaxial); For details see the attached figure 2. 1.54 Since mineral is uniaxial negative so RI of o-ray should be greater than RI of e ray. Out of two given RI value (1.54 and 1.55) the higher one will correspond to o-ray and lower one will correspond to E-ray. So RI for E-ray will be 1.54 3. Ans= 0.01 Birefringence = RI(o-ray) - RI (E-ray) = 1.55 - 1.54 = 0.01
![cropped4726387027362895582.jpg]()
-
![comment-profile-img]()
>
Sajan sarthak
![best-answer]()
1.optic sign is optically negative. as slow ray is o -ray 2. E ray has refractive index 1.54. 3. birefringence is (1.55-1.54)= 0.01 i.e ( slowray -fast ray) refractive index
Do You Want Better RANK in Your Exam?
Start Your Preparations with Eduncle’s FREE Study Material
- Updated Syllabus, Paper Pattern & Full Exam Details
- Sample Theory of Most Important Topic
- Model Test Paper with Detailed Solutions
- Last 5 Years Question Papers & Answers
Sign Up to Download FREE Study Material Worth Rs. 500/-
Rahul kumar
There is a minor correction in part (iii) of this question. Here for this particular section shown in the question (looking down the optic axis i.e. circular section) the birefringence value will be 0 because we can only see one RI even after rotation of 360 degrees. For principal section (which is not shown here) the birefringence value will be maximum i.e. 0.01; Refer to the attached figure.