Physics · Class 10 · Chapter 1 | Light – Reflection & Refraction
Physics Notes
Class 10 — Chapter 1
Light: Reflection and Refraction
Name: ______________________
Roll No: _______ Section: ______
Date started: __ / __ / ____
What this chapter covers
1. Laws of reflection & types of reflection
2. Spherical mirrors – concave and convex
3. Mirror formula, magnification, sign convention
4. Refraction of light, refractive index
5. Spherical lenses – convex and concave
6. Lens formula, magnification, power of a lens
Remember: Light is a form of energy that lets us see objects. It travels in straight lines (rectilinear propagation) and shows
both reflection and refraction at surfaces.
1
, Physics · Class 10 · Chapter 1 | Light – Reflection & Refraction
1. Reflection of Light
When light falls on a polished/shiny surface and bounces back into the same medium, it is called reflection of light.
Laws of Reflection
1. The incident ray, the reflected ray and the normal at the point of incidence all lie in the same plane.
2. The angle of incidence is always equal to the angle of reflection, i.e. ∠i = ∠r
Normal
Incident ray Reflected ray
i r
Plane mirror
Angle of incidence (i) = Angle of reflection (r), both measured from the Normal
These two laws hold for reflection at any surface – plane or curved.
A few everyday examples
We see our face in a mirror because of reflection.
Periscopes used in submarines work using two plane mirrors.
Kaleidoscopes use multiple reflections to form patterns.
2
Physics Notes
Class 10 — Chapter 1
Light: Reflection and Refraction
Name: ______________________
Roll No: _______ Section: ______
Date started: __ / __ / ____
What this chapter covers
1. Laws of reflection & types of reflection
2. Spherical mirrors – concave and convex
3. Mirror formula, magnification, sign convention
4. Refraction of light, refractive index
5. Spherical lenses – convex and concave
6. Lens formula, magnification, power of a lens
Remember: Light is a form of energy that lets us see objects. It travels in straight lines (rectilinear propagation) and shows
both reflection and refraction at surfaces.
1
, Physics · Class 10 · Chapter 1 | Light – Reflection & Refraction
1. Reflection of Light
When light falls on a polished/shiny surface and bounces back into the same medium, it is called reflection of light.
Laws of Reflection
1. The incident ray, the reflected ray and the normal at the point of incidence all lie in the same plane.
2. The angle of incidence is always equal to the angle of reflection, i.e. ∠i = ∠r
Normal
Incident ray Reflected ray
i r
Plane mirror
Angle of incidence (i) = Angle of reflection (r), both measured from the Normal
These two laws hold for reflection at any surface – plane or curved.
A few everyday examples
We see our face in a mirror because of reflection.
Periscopes used in submarines work using two plane mirrors.
Kaleidoscopes use multiple reflections to form patterns.
2
