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                                        SAI INTERNATIONAL SCHOOLL
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                                                        Class 6
                                                   Lesson Notes
                                                 Subject- Physics
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                                    Ch. – Light, Shadows and Reflectionn
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                            Subtopic- Transparent, Translucent and Opaquee;
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                                        Rectilinear propagation of lightt
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               NOTES:
               A substance through which light propagates, act as s medium.
               A   s u b st a n c e   t h r o u g h   w h i ch   l i g h t   p r o p a g a t e s,   a c t   a

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               1.  transparent
               2.  translucent
               3.  Opaque materials.

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               Materials through which light can pass ss completely are called transparent
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               materials. For e.g. air, water, glass etc.c.
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               Materials through which lighht can propagate partially are known as translucent
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               Materials through which light  cannot propagate are known as opaque materials.
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               For e.g. wall, wood, stone etc.c.


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               Rectilinear propagation of light..
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               The property of light that it travels in a straight line is known ass rectilinear

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               propagation of light.

               A narrow group of light rays considered as a  beam.
               A   n a r r o w   g r o u p   o f   l i g h t   r a y s  co n si d e r e d   a s  a


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                 In a beam of light from a small source, the rays are moving away from each
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                    other. Such rays are called  divergent rays.

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                 In a beam of light from a very large source which is located far away, the rays of

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                    light is taken as parallell to each other.

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                 When rays of light meet at a common point, they are called  convergent rays.
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