Light

Unit 1

Light

Learning Objectives

The students will be able to

* understand that light is an energy

* differentiate natural and artificial light sources

* understand rectilinear propagation of light

* understand formation of shadows

* know reflection of light and its types

* know the laws of reflection

* understand the properties of the images formed in a plane mirror

 * understand dispersion and spectrum

* understand synthesis of colors

Introduction

When you enter into a dark room, nothing is visible. The moment you switch on the light, everything in the room becomes visible. How do we see things with our eyes? When you look at this book, the light falling on the book is reflected and enters your eyes. Light is a type of energy that helps us to see all the things around us. Light can be detected by the human eye. We all know that light is essential for vision. Let us see more about light in this chapter

Light is the only source of energy for plants. So, they entirely depend on light. People and animals derive energy from carbohydrates, protein and fat through their food. Plants produce food using the energy from Sun light, carbon-di-oxide and water by the process called as Photosynthesis. Sun light acts a vital role in the process of photosynthesis.