If the angle of incidence is equal to the critical angle, what is the behavior o
Practice Questions
Q1
If the angle of incidence is equal to the critical angle, what is the behavior of the light ray?
It is refracted at 90°.
It is totally internally reflected.
It is absorbed.
It is transmitted.
Questions & Step-by-Step Solutions
If the angle of incidence is equal to the critical angle, what is the behavior of the light ray?
Correct Answer: Light ray is refracted at 90°.
Step 1: Understand what the angle of incidence is. It is the angle between the incoming light ray and the normal (an imaginary line perpendicular to the surface).
Step 2: Know what the critical angle is. It is the specific angle of incidence at which light can no longer pass into the second medium and instead reflects back.
Step 3: When the angle of incidence is equal to the critical angle, the light ray does not enter the second medium but instead travels along the boundary between the two media.
Step 4: At this point, the light ray is refracted at an angle of 90° to the normal, meaning it is parallel to the boundary.
Step 5: This situation marks the threshold for total internal reflection, where any angle greater than the critical angle will result in the light being completely reflected back into the first medium.
Critical Angle – The angle of incidence at which light is refracted at 90° along the boundary between two media.
Total Internal Reflection – The phenomenon that occurs when the angle of incidence exceeds the critical angle, causing light to reflect entirely within a medium.
Refraction – The bending of light as it passes from one medium to another, depending on the angle of incidence and the refractive indices of the media.
