What will happen if we thought that, we can’t see the world of colors through our eyes? It is impossible to think the things like that. Hundred decades ago, there were televisions which are black and white in color only even though that time we saw the colorful world with our eyes. The science is developing rapidly and we are facing the real magic of science in daily life. All the credit of our visualization goes to light. If there is no source of light then there will be no visualization.
Optics: The branch of physics dealing with the study of light is called optics.
We study light in the branch of optics. How do we see objects? When light is incident on any object then that object reflects the light which is incident on the retina of our eyes and an image of that object will form& finally we get visualization of that object. The various colors of different objects is due to the light of different wavelengths reflected by them. There are many phenomenon happening in the environment which explains the wonders of light like reflection, refraction, scattering, dispersion etc. the blue color of sky, rainbow, mirror images, beautiful colors of wings of butterfly all are the wonders of light. The ray of light coming from the sun always travels in a straight line path which we called as rectilinear propagation of light. In short, “Ray of light is the radiant energy which produces sensation of light traveling in a straight line.” Before proceeding to this concept we define light first.
Light: light is an electromagnetic wave which gives sensation of vision.
Light has dual nature. According to the above definition we consider light as a wave but light has particle nature also. In this chapter we consider particle nature of light. Particle nature follows rectilinear propagation of light. This chapter includes the optical phenomenon like reflection, refraction which explains the rectilinear propagation of light & also wave nature of light. Beside this we can see how the images are formed using mirrors in detail.
Do you know?
The light having rectilinear property of propagation get bended around the edges of an opaque bodies like wood, bricks, stones etc. Later this explained the phenomenon of diffraction. There are many phenomenon related to light such as interference, polarization which all explains the wave nature of light. But later on according to quantum mechanics it will proved that light has particle nature also.
Thus it has been proved that light has been proved that light has dual nature i.e. particle as well as wave nature.
Reflection of Light:
When a ray of light incident on a reflecting surface of medium, the light will be sent back into the same medium is called as reflection of light.
Reflection of light- Bending of light un same medium is called reflection.
The laws of reflection for any mirror are as given below:
- First law: The incident ray, reflected ray and normal lies in the same plane.
- Second law: The angle of reflection is always equal to the angle of incidence.
- Third law: The incident ray & reflected ray lie on the opposite sides to that of normal.
We all know that, the image produced in a plane mirror is virtual and its size is always similar to object. In case of plane mirror the image is formed behind the mirror and it is laterally inverted. The reflection from the shining surface polished surface is called as regular reflection.
The reflection of light from different shaped mirror is totally different. If you have visited to mirror house, then you there you have saw that various shaped mirror has used & the images produced are also different and animatic. But the commonly used shaped mirror is spherical mirror which has vast applications in optics. Let us discus about the spherical mirror in detail.
Fig. Regular reflection of light
- Take a shining curved bowl. Try to see your face in its outside curved area.
- What type of image you will get?
- Now, reverse the bowl & see your face from inner side of bowl, observe the image.
- What is your conclusion after getting both image?
- Which type of mirrors are used in vehicles?
- What are the real life examples of reflection you know?
- Which type of mirrors are used in salon, parlors & why?