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Light - Coggle Diagram

- - - - Reflection
        
        When light falls on a shiny surface, it bounces back. This phenomenon is called reflection. We are able to see images in mirrors or in water, because of reflection.
        
        Reflection from a Rough Surface
        
        Most of the objects on Earth have rough surfaces. These type of objects scatter the light that falls on them in different directions. Example - Sweater, Roads, Doors, Tables, Chairs, Electronic Devices, etc.
        
        The reflection that takes place on such surfaces is irregular and no images are formed.
        
        Reflection of Light from a Smooth Surface
        
        Regular Reflection of Light from a Plane Surface
        
        Periscopes
        
        Periscopes are an application of reflection by plane mirrors.
        
        Periscopes are 2 plane mirrors placed in a peculiar way to make things visible.
        
        Some examples of objects with smooth surfaces are Glass, Water, Polished Metal, etc.
        
        When this type of reflection takes place light rays don’t get scattered and an image is produced.
        
        Types of Images
        
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        Reflection of Light from a Plane Mirror
        
        Angle of Incidence
        
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        Angle of Reflection
        
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        Plane Mirror
        
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        Image
        
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    - - There are certain objects through which light cannot pass, and it changes its path after hitting the object. These are called Opaque objects. Some examples are wood, mobile phone and us humans.
        
        Shadows
        
        Transparent, Translucent and Opaque Shadows
        
        The object must be opaque or translucent to make a shadow.
        
        A transparent object will not make any shadow, as light will pass straight through it.
        
        Opaque objects make dark shadows. Translucent objects make faint shadows.
        
        Formation of Shadows
        
        A shadow is made when an object blocks light. The shadow appears on the side of the object furthest from the light source.
        
        Size and Intensity of Shadows
        
        Size of the light source
        
        A small light source gives a sharp shadow that is equally dark all over.
        
        A larger light source gives a shadow with a dark central region and a lighter shadow surrounding it.
        
        Umbra Region
        
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        Penumbra Region
        
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        Distance between the light source ad the object
        
        A light shadow is formed when the light source is close to the object and a dark shadow is formed when the light source is farther from he object.
    - - Translucent materials allow light to pass through them, but they diffuse the light in a way that make objects on the opposite side appear blurred. Examples of translucent materials are frosted glass, oil paper, some plastics, ice and tissue paper.
    - - If light hits an object and passes through it, that object is known as a transparent object.
        
        Refraction
        
        Light gets refracted when the incident ray is 90 degrees to the surface of the material.
        
        Refraction is the bending of light. It happens due to change in speed of light.
        
        Light travels at different speeds in different media.
        
        From a rarer medium to a denser medium.
        
        In this light bends towards the normal.
        
        From a denser medium to a rarer medium.
        
        Light bends away from the normal.
        
        Normal
        
        Normal is a line that’s perpendicular (at 90 degrees) to the surface where the incident ray strikes.
        
        Refracted Ray
        
        Light Ray that gets refracted after it strikes the surface.
        
        Angle of Incidence
        
        It is the angle between the incident ray and the normal.
        
        Angle of Refraction
        
        It is the formed by the refracted ray and the normal.
        
        Incident Ray
        
        Light Ray that fall on the surface.
        
        Prism
        
        Prism is a glass or a plastic block with a triangular cross section.
        
        When a ray of sunlight passes through a prism, it splits into seven colours. This is known as Spectrum.
        
        Rainbow
        
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        VIBGYOR
        
        Each colour produced has a different wavelength.
        
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- - - - Coloured Paint
        
        Primary Colours
        
        Yellow, Magenta, and Cyan
        
        Mixing all of them together produces black
        
        They can be combined in different proportions to produce a wide range of colours
        
        The pigment absorbs some of the colours of light and reflects others,
        
        This gives the pigment its distinct colour.
        
        Paint contains tiny particles known as pigment
      - Coloured Light
        
        Lights of different colours combine to form other colours.
        
        Primary Colours
        
        They combine to form Secondary colours
        
        Red, Blue and Green
        
        These are set of 3 colours which can combine to form all other colours.
        
        Mixing all of them produces white
    - - Sheets of Coloured plastic and glass can filter the colours.
        
        They absorb some colours and allow the other colours to pass-through.
        
        They produce different coloured light.
        
        Eg. A blue filter allows only blue light to pass through.
        
        Eg. A red allows only red light to pass through.
        
        Used in
        
        Theatre for added effects
        
        Scientific Investigations
        
        Photography for Art exhibitions, Advertising campaign
    - - The Object may reflect all the different colours. If this happens then it’s colour appears to be white.
      - The Object may absorb all the different colours. In this case the colour appears Black.
      - The object may absorb some colours and reflect the others.
        
        The colour of the object is a combination of the colours reflected.
        
        Eg. A yellow sunflower appears to be yellow as it absorbs all other colours and reflect yellow.