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SAI INTERNATIONAL SCHOOL

                                                         Class 6
                                                     Lesson Notes
                                                   Subject- Physics

                                           Ch. – Electricity and Circuits
                                               Subtopic- Electric Bulb



               Electric blub:
                     Bulb is a device that converts electrical energy into heat and light energy.
                     Construction:
                          o  It consists of transparent glass covering, coiled metal wire known as the
                              filament made up of tungsten metal.
                          o  Filled with inert gases such as argon, neon etc.
                     Working:
                          o  When electricity flow through the filament, it’s get heated and glows, it
                              gives the light.
























               (Note:

                     Tungsten metal is used to made filament of the bulb because of the following
                       reason:
                                   Tungsten metal have high melting point
                                   It also has high resistance for which it can produce high amount of
                                     heat.

                     Importance of transparent glass covering in electric bulb:
                                The glass, cover the filament and prevent it from reacting with oxygen
                                 due to which it will break and transparency of glass allow the light to
                                 pass.
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