Ice has a critical angle of 49.8 degrees, explain or rectangular prism of clear ice can be used for the total internal reflection of light by 90 degrees
Just multiply the optical fibres by the guiding liquid and you will get the answer for the glass block.
To understand why a rectangular prism of clear ice can be used for the total internal reflection of light by 90 degrees, we need to start by understanding a few key concepts.
1. Refraction: Refraction is the bending of light as it passes through a medium of different optical density. When light enters a medium at an angle, its direction changes due to the change in speed caused by the change in medium. This change in direction is known as refraction.
2. Critical Angle: The critical angle is the angle of incidence at which light traveling from a medium with a higher refractive index to a medium with a lower refractive index will undergo total internal reflection. Beyond the critical angle, instead of refracting through the second medium, the light is entirely reflected back into the first medium.
Now, let's apply these concepts to the scenario of a rectangular prism of clear ice.
Ice has a refractive index of about 1.31 for visible light. This means that light travels slower in ice than in air. When light passes from air to ice, it undergoes refraction because the speed of light changes. The exact amount of bending depends on the angle of incidence and the refractive indices of the two media involved.
To achieve total internal reflection, we need the light to be incident on the ice-air interface at an angle greater than the critical angle. For ice, the critical angle is approximately 49.8 degrees. This means that if light is incident on the ice-air interface at an angle greater than 49.8 degrees, it will reflect back into the ice instead of refracting into the air.
By forming a rectangular prism out of clear ice, we can manipulate the angles of incidence and reflections to guide the light through the prism and achieve a 90-degree reflection. Here's a step-by-step process:
1. Imagine a rectangular prism shape made of ice, with three perpendicular faces.
2. Let the incoming light (from a source) enter one face of the prism at an angle greater than the critical angle (i.e., greater than 49.8 degrees).
3. Due to total internal reflection, the light will reflect off the adjacent face at the same angle but in the opposite direction, maintaining the 90-degree angle.
4. The light will continue reflecting off the next face, again maintaining the 90-degree angle.
5. Finally, the light will exit the prism through the third face, changing its direction.
In this way, a rectangular prism of clear ice can effectively bend the path of light by 90 degrees using total internal reflection.