#reflection_of_light ‪@seetolearn2266‬
#Light
#specular_reflection
#diffusedreflection
#physics

1)#Light is a form of #energy.
2) I'm holding a #mirror in the path of light.
The light bounces off from the surface of the mirror which you can see on the wall .
3) This bouncing back of light after striking surface of an object is called reflection of light.
4) The light that falls on the #mirror is called the #incident_light.
5) A perpendicular at the point of incidence is called the #normal and the light that bounces off the mirror is the reflected light.
6) We can seen the reflected light on the wall.
7) Since light travels in a straight line, we use the concept of ray from mathematics to show the path of light.
8) So this is how we show the incident ray and the reflected ray.
9) The angle angle between the incident ray and the normal is called the #angle_of_ incidence while the angle between the reflected ray and the normal is called the #angle_of_reflection.
10)This phenomena of reflection is governed by certain laws called #lawsofreflection.
11) To study them we will perform an activity in dark using a light source like a torch or a bulb , a box with a slit.
12) A plane mirror which is kept on a small disc having markings like a protractor.
13) We have to keep the torch in front of the box, in such a way that only a narrow light falls on the mirror through the slit. This is the incident light.
14) Here you can see the digit below the #incident light is 60 degrees. This line drawn on the marking zero is the normal.
15) So the angle of incidence is 60 degrees.
16) We can see that the digit below the #reflected light is also 60 degrees. In other words the angle of reflection is 60 degrees.
17) Let's note down these two values of incident and reflected angles.
18) Now what if the angle of incidence is 30 degrees?
19) The angle of reflection is also the same 30 degrees.
20) Let's reduce the angle of incidence to zero. Now the incident light is perpendicular to the surface of the mirror.
21) What we see here is the reflected light bounces off in the same direction, which means the #reflected light is also perpendicular to the surface of the mirror.
22) Thus when the incident angle is zero, the reflected angle is also zero.
23) What do we deduce from these observations?
24) Correct, the angle is #incidence is equal to the angle of #reflection.
25) This is what first law of reflection of light states.
26) The second law states that the incident ray, the reflected ray and the normal at the point of incidence all lie in the same plane.
27) So, you can see here that all of them lie on this disc which represents a plane.
28) You know that an image can be seen on shiny and smooth surface like that of a mirror, stainless steel vessel, still water etc.
29) But why can't a surface of paper, cardboard or ground form images?
30) Doesn't it reflect light?
31) The truth is all surfaces reflect light that falls on them.
32) However, depending upon the surface, the reflection can be specular,also called regular or diffused also called irregular.
33) When parallel incident rays fall on a smooth and shiny surface, the reflected rays are also parallel.
34) This is called specular or regular reflection of light. An image is formed due to specular reflection of light.
35) When the parallel incident rays fall on a rough surface, the reflected rays are not parallel. This is called diffused or irregular reflection of light.
36) An image cannot be formed due to diffused reflection of light.
37) This phenomenon of reflection is very important in our life.
38) We can see an object around us only if the light reflected by it enters into our eyes.
38) Thus for the object to be visible the light reflected by it should enter into our eyes.


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