Light – Reflection and Refraction Class 10 Notes

What is Light?

Light can be simply defined as the form of energy which helps us to see objects in dark. There are both natural and artificial sources of light. Sunlight is the best example for the natural sources of light. Reflection and refraction of light are the two main properties of light.

What is Reflection of light?

The natural phenomenon of bouncing back the light in the same medium on striking the surface of an object is termed as the Reflection of light. According to the laws of Reflection:

The angle of reflection is always equal to the angle of incidence.

All the three rays- incident, reflected ray and the normal lie in the same plane.

What is Refraction of light ?

The natural phenomenon of changing the path of light while moving from one medium to another is termed as the Refraction of light.

As the light travels from its rarer to a denser medium, light rays bend towards normal and while traveling from the denser to a rarer medium, light rays bend away from normal. According to the law of Refraction:

The Refraction of light occurs when there is a change in the speed of light and when the light rays enter from one transparent medium to another.

Few Important Questions

  • Difference between Reflection and Refraction of light.
  • Difference between Concave mirrors and Convex mirrors.
  • What is a spherical mirror? List out the uses of spherical mirrors.

Learn more about light, reflection and refraction of light from the topics given below:

Practise This Question


What can be inferred from the above reaction?

(i)  CaO is solid.

(ii) CaO is reactive with water.

(iii) H2O is liquid.

(iv) H2O is in vapour state.

(v) Ca(OH)2  forms a solution with water

(vi) The reaction is exothermic.