What is the angle of incidence of a ray of light falling along the normal on a glass strip?
- AOption (a)
45°
- BOption (b)
0°
- COption (c)
90°
- DOption (d)
30°
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Correct answer
0°
Why this answer is correct
The correct answer is 0º.
Key Points
- The angle of incidence is defined as the angle between the incident ray and the normal to the surface at the point of incidence.
- When a ray of light falls along the normal, it means the ray is perpendicular to the surface.
- In this situation, the incident ray is aligned with the normal, making the angle of incidence 0º.
- This concept is crucial in understanding how light behaves when it strikes different surfaces, influencing reflection and refraction.
Additional Information
- Angle of Incidence
- The angle of incidence is the angle formed by the incoming ray and the perpendicular (normal) to the surface at the point of contact.
- It is a fundamental concept in the study of optics, particularly in the laws of reflection and refraction.
- The angle of incidence is measured in degrees.
- Normal Line
- The normal line is an imaginary line perpendicular to the surface where the ray of light hits.
- It is used as a reference to measure angles of incidence and reflection.
- Reflection and Refraction
- Reflection occurs when light bounces off a surface. The angle of incidence is equal to the angle of reflection.
- Refraction happens when light passes from one medium to another, changing its speed and direction.
- The relationship between the angle of incidence and refraction is described by Snell's Law.
- Applications in Real Life
- Understanding angles of incidence is crucial in designing optical devices such as lenses, mirrors, and prisms.
- It is also important in fields like photography, astronomy, and even in the development of various technologies like fiber optics.


