If the angle of incidence is equal to the critical angle, what is the behavior of the light ray?
Practice Questions
1 question
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.
When the angle of incidence equals the critical angle, the light ray is refracted along the boundary at 90°, marking the threshold for total internal reflection.
Questions & Step-by-step Solutions
1 item
Q
Q: If the angle of incidence is equal to the critical angle, what is the behavior of the light ray?
Solution: When the angle of incidence equals the critical angle, the light ray is refracted along the boundary at 90°, marking the threshold for total internal reflection.
Steps: 5
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.
