K.asish Subudhi posted an Question
September 04, 2021 • 16:22 pm 30 points
  • Geology (GG)

Number of optic axes in isotropic substance is: (a) 2 (b) 3 c) 4 (d) infinite

Number of optic axes in isotropic substance is: (A) 2 (B) 3 C) 4 (D) Infinite

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    Saurabh 1 best-answer

    Well this question seems to be the one that checks your basic knowledge about optic axis. I assume that you might be knowing beforehand about the optic axis and also the optical properties associated with this specific axis. Actually optic axis defines the axis along which there seems to be abnormal behaviour of light due to no double refraction resulting from no birefringence . For uniaxial crystals, cardinality of this axis is one while for biaxial crystals , just add one and hence two optic axes in case of biaxial crystals. Also in case of isotropic minerals substances there isn't any observable change in the optic behavior along the specific direction and it posses no double refraction and no birefringence. Irrespective of where you are observing and at what certain point you are observing, it will never ever show birefringence hence no double refraction. So from this , you can conclude that there are mathematically infinite number of optic axis possible in case of isotropic substances. So correct option should be (D).


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