Light class 8 of NCERT of science including reflection and refraction

Nice presentation on light

1. Light Class 8 Science

2. Introduction to Light • Light is a form of energy that enables us to see the objects around us. • Key Properties: - Light travels in a straight line. - Light can be reflected, refracted, or absorbed.

3. Reflection of Light • The bouncing back of light when it strikes a surface. • Key Terms: - Incident Ray: The ray that falls on a surface. - Reflected Ray: The ray that bounces off. - Normal: Perpendicular line to the surface. • Laws of Reflection: 1. Angle of incidence = Angle of reflection. 2. Incident ray, reflected ray, and normal lie in the same plane.

4. Types of Mirrors • Plane Mirror: - Forms a virtual and upright image. - Image size is equal to the object size. • Spherical Mirrors: - Concave Mirror: Can form real or virtual images. - Convex Mirror: Always forms virtual and diminished images.

5. Refraction of Light • The bending of light when it passes from one medium to another. • Examples: - A pencil appears bent in water. - Lenses in spectacles use refraction.

6. Dispersion of Light • The splitting of white light into its constituent colors. • Example: Formation of a rainbow. • Colors of Spectrum: Violet, Indigo, Blue, Green, Yellow, Orange, Red (VIBGYOR).

7. Human Eye and Light • Structure of the Eye: - Cornea, lens, retina, and optic nerve. • Functions: - Light enters through the cornea and forms an image on the retina. - The optic nerve sends signals to the brain for interpretation.

8. Applications of Light • Mirrors and lenses in optical instruments. • Fiber optics in communication. • Solar panels converting light to electricity.

9. Summary • Light is a form of energy. • Reflection and refraction are key phenomena. • Light enables us to see and has various applications.

10. Thank You What have you learned about light today?