Question

Choose the right option for the brilliance of a diamond?

• A. Total internal reflection
• B. Reflection
• C. Shape
• D. Cutting

Answer 1

The correct option is A

Total internal reflection

The explanation for the correct option:

In the case of option ($\mathrm{A}$):

1. In physics, total internal reflection refers to the total reflection of a beam of light from the surrounding surfaces back into a material such as water or glass.
2. When the angle of incidence exceeds a particular limiting angle, known as the critical angle, the phenomenon happens.
3. The essential angle for a water-air surface is$48.5°$.
4. Because refraction indices are wavelength dependent, the critical angle (and the angle of total internal reflection) varies significantly with wavelength and, thus, with color.

Hence, option ($\mathrm{A}$) is correct.

The explanation for the incorrect options:

In the case of option ($\mathrm{B}$):

1. At an interface between two different media, reflection is the change in the direction of a wavefront so that it returns to the medium from which it came. Reflection is not the phenomenon that causes the brilliance of a diamond.
2. Hence, option ($\mathrm{B}$) is incorrect.

In the case of option ($\mathrm{C}$):

1. In contrast to other attributes such as color, texture, or material type, a form or figure is the graphical depiction of an item or its exterior border, outline, or external surface. The shape is not the phenomenon that causes the brilliance of a diamond.
2. Hence, option ($\mathrm{C}$) is incorrect.

In the case of option ($\mathrm{D}$):

1. Cutting is separating or opening a physical item into two or more parts with an acutely directed force.
2. Cutting a diamond provides its shape and does not cause the brilliance of a diamond.
3. Hence option ($\mathrm{D}$) is incorrect.

Hence, option ($\mathrm{A}$) is the correct option.