Nature and Properties of Light

Basics of the Speed of Light

1. The speed of light in a vacuum is the fastest possible speed in the universe, approximately 3 × 10⁸ m/s.
2. In any other medium, light travels slower than it does in a vacuum due to interactions with the medium's particles.
3. The ratio of the speed of light in a vacuum to its speed in a medium gives the refractive index of the medium (n = c/v).
4. A higher refractive index indicates a slower speed of light in that medium.

Speed of Light in Various Media

Reflection of Light

1. Reflection is the phenomenon where light bounces back from a surface.
2. The law of reflection states that the angle of incidence (i) is equal to the angle of reflection (r).
3. Reflection occurs at the boundary of two mediums, such as air and a mirror.
4. Reflection can be regular (on smooth surfaces) or diffuse (on rough surfaces).
5. Plane mirrors produce virtual, upright, and laterally inverted images.
6. Spheric