Page 1 - Lesson notes- Types of charge and their interaction
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SAI INTERNTIONAL SCHOOL
                                                         Class 8
                                                    Lesson Notes
                                                  Subject- Physics
                                         Ch- Some Natural Phenomena
                              Subtopic- Types of charge and their interaction

          Definition of Natural Phenomena: These are the Phenomena which occur in nature, naturally
          and we don’t have a control over it. They can be destructive in nature and cause damage to
          human life and property.
          Examples of some destructive natural phenomena are Earthquake, volcanoes, cyclone,
          tsunami, lightning, storms.

          Electric charge: Electric charge is the fundamental physical quantity which determines the
          electrical properties of an object.
          Types of charges: There are two types charge: Positive charge and negative charge.
          Interaction of charges: The oppositely charged objects always attract each other and similarly
          charged objects always repel each other. Any charged body will attract a neutral body.

          Static charge: the electric charge generated by friction or by rubbing are called static charges.
          They are localized and do not move.
          Example:
          l  Glass rod when rubbed with silk acquires positive charge.
          l  Ebonite rod when rubbed with fur acquires negative charge.


          Interactive Elements / Activities:
          Charge Interaction Experiment: Use balloons or plastic rods rubbed with wool/silk to
          demonstrate attraction and repulsion.
          Group Prediction Game: Present charge combinations
          (positive–positive, positive-negative, charged-neutral) and ask students predict outcomes.
          Match-the-Pair Activity: Match the object
          (e.g., glass rod, ebonite rod) with the charge it acquires after rubbing.
          Simple Demonstration: Show how small paper bits are attracted to a charged comb.

          Real-Life Application Examples:
          Shocks from Doorknobs in Winter: Caused by build-up of static charge on the body due to
          friction.
          Lightning During a Storm: A massive discharge of static charge between clouds or between
          cloud and Earth.
          Photocopiers and Laser Printers: Use static charge to attract toner particles to paper.
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