Reflection of Light
Can you see things around you right now? If yes, then it is mainly due to the light that is falling on those objects. When a ray of light falls on any object or anybody that is rough, smooth, or shiny, the surface of those objects bounces back those rays to our eyes. This incredible phenomenon is called the reflection of light. The only difference is that when light falls on an object with a shiny surface such as a mirror and plates, a crisp reflection or image is formed. This is because the reflection of light is uniform throughout the surface of the object. On the other hand, when light falls on an object with a rough surface such as a granite slab or polished shoes, a coarse image is formed because the reflection of light is non-uniform. When light falls on a much more irregular surface such as cemented floor or walls, the reflection is arbitrary, and hence no image is formed.
Reflection of Light Definition
Reflection of the light definition is quite simple and easy to understand. When you find a ray of light falling on a smooth object and then bouncing back, it is known as the reflection of light. It can be explained through this simple diagram.
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(the image shows the Reflection Of Light Image Diagram. Here: the incident ray is denoted by ‘i’; Reflected ray is denoted by ‘r’; P is the point of perpendicular)
In the diagram shown above, the ray of light that falls on the mirror is known as incident ray and is denoted by small ‘I’, and the ray that bounces back is known as reflected ray and is denoted by small ‘r’. The point where incident ray falls, a perpendicular is drawn, which is known as ‘normal’. This normal line basically works as a division between the reflected ray as well as the incident ray equally and even offers an “angle of incidence” and “angle of reflection”.
The above discussion gives us the Law Of Reflection of light that says:
The angle of incidence and reflection are equal.
The reflected ray, the normal and the incident ray, they all fall in the same plane.
Types of Reflection
There are mostly two types of reflection, one is the regular reflection, and the other is irregular reflection.
Regular Reflection- a regular reflection is basically known as a mirror-like reflection. In this case, the rays of light coming from an object will be falling on a smooth as well as a shiny object such as a mirror and then being reflected at a definite angle. Here, as per the theory of reflection, both the angles of incidence and reflection will be equal to each other. Thus it forms a crisp and clear image of the object. This is because the light falls on a smooth and shiny surface.
Irregular Reflection- this type of reflection is not similar to a mirror-like reflection. In this type of reflection, you can find the ray of light falling on an irregular object possessing a rough surface such as a water surface. As per the theory, such a surface will reflect the light in all possible directions. However, both the angles of the incident and the reflection, in this case, are not at all equal. Therefore, it will not form an image or a very rough image.
Virtual Image and Real Image
A mirror can create two different types of images, virtual image, and real image. When light from any single source spreads out after passing through a lens after being reflected, a virtual image is formed. When light falls on a mirror, the image will always appear to be behind the mirror, but this is impossible since the light does not pass through the image but is reflected. This way a virtual image is created by the reflection of light from a mirror. Therefore it is clear that any image we see from the reflection of light by a plane flat mirror is always a virtual image. The concept of the virtual image will be clearer with the help of the image given below.
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(The image displays the concept of virtual image with the help of incident rays and reflected rays)
On the other hand, real images are formed when the rays of light pass through the lens and meet or converge at a single point on the other side of the lens. Since the rays are converging, it means that the image, which is formed, actually exists. Therefore you place a screen on the path of the real image the image will be created on the screen. Short and simple, virtual image occurs when the ray of light does not meet but appears to meet, and the real image is formed when rays of light actually meet. You can understand the concept of the real image with the help of the following diagram.
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(The image displays the concept of real image with the help of positioning of objects)
1. How can you Differentiate Between the Real Image and the Virtual Image?
The image in the real image is formed due to the reflection or refraction. It is formed when the light arises from an object and meets at a certain point.
It is easy for a person to capture the real image on a screen. Now, this happens because the image here is formed due to the actual intersection of a ray of light.
However, the image formed with the help of the real image is basically an inverted image which is formed at the back of the lens.
People use converging lenses to produce a real image.
The virtual image is produced when the light coming from an object appears to hit a certain point.
It is impossible to capture virtual images on a screen because it is the imaginary intersection of the ray of light.
The image formed is an erect image and not an inverted one.
People use diverging lenses to produce the image.
2. What Type of Image is Formed on a Cinema Screen?
The type of image that is formed by the cinema screen is the real image. The real image is the image that actually exists. This is because the reflected rays meet at a point behind the lens. The projectors of the cinemas generate real images with the help of cameras and lenses.