Question

A calcite crystal is placed over a dot on a piece of paper and rotated. On seeing through the calcite, one will see:
A. One dot
B. Two stationary dots
C. Two rotating dots
D. One dot rotating about the other.

Answer 1

Hint: First of all, we will analyse the different properties of calcite crystal, one of which is birefringence. Going through this property we can answer the given question.

Complete step by step answer:In the given question, we are given a calcite crystal and it is placed on a piece of paper over a dot.
After that we rotate the arrangement. Then we look through the calcite crystal. According to a person there will be many various observations, but without actually looking through the calcite crystal, we need to predict what the observation will be.
We know calcite is part of the mineral calcite group, a group of similar carbonates that are isomorphous to each other. In certain physical properties, they are identical, and can partially or completely substitute each other, forming a solid solution series.
In calcite crystal, there occurs image splitting and change in the orientation of the axis of rotation of a body which is rotating. This phenomenon is known as birefringence of calcite.
In fact, calcite birefringence is so efficient that there are not only two waves, but the paths of the two waves are also separated. The ordinary light, one of the waves, moves straight through, with its picture staying stagnant when the crystal is turned. This ray is called the ordinary ray since, in an ordinary manner, it acts (is refracted). So, we get two images, one is fixed and the other rotates about the other image.
The correct option is D.

Note:Calcite is a mineral found in the Earth 's crust that is very abundant. In sedimentary rock it is located. Calcite comprises carbon, calcium, and oxygen, known collectively as calcium carbonate.Calcite could form on top of another mineral as an undesirable coating. By soaking it in vinegar, calcite will quickly be melted out.