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Electric charges

1Can a rubbed ruler attract smoke?. Yes, it can attract smoke.. Why?. It is because the ruler carries charge after rubbing and charged objects can attract neutral objects, like smoke.. 2Can a rubbed ruler attract smoke after some air is blown to it?. No, it cannot attract smoke.. It is because air blown to the ruler forms a layer of moisture on the ruler. This enables electrons to move on the ruler and neutralize the charge on it..

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Electric charges

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    1. Electric charges

    2. 1 Can a rubbed ruler attract smoke?

    3. 2 Can a rubbed ruler attract smoke after some air is blown to it?

    4. 1 Two kinds of charges After being rubbed, plastic ruler can attract paper scraps.

    5. Observe what happens when 2 rubbed plastic strips are brought close.

    6. Rubbed acetate/polythene strips repel. 1 Two kinds of charges

    7. Unit of charge Unit of charge: coulombs (C)

    8. Where do charges come from? Matters are made up of atoms.

    9. If electrons no. = proton no. ? neutral Where do charges come from?

    10. When a duster rubs an acetate strip... Where do charges come from?

    11. Similarly, when a duster rubs polythene strip... Where do charges come from?

    12. Rubbing materials does NOT create electric charges. It just transfers electrons from one material to the other. Where do charges come from?

    13. Insulators and conductors Insulators: materials that do NOT allow electrons to flow through them easily.

    14. 4 Insulators and conductors

    15. Attraction of uncharged objects When charged rod is put near a metal foil...

    16. Attraction of uncharged objects Similarly, when charged rod is close to paper scrap...

    17. Example 1 A and B are identical metal-coated balloons.

    18. Example 1 A and B are identical metal-coated balloons.

    19. Q12 Acetate rod has...

    21. Q3 How does a positively... How does a positively charged rod attract a neutral object?

    22. Earthing An object is earthed when it is connected to the earth through a connecting wire.

    23. Earthing

    24. Earthing

    25. Fun with electric charges Van de Graaff generator can produce a large amount of negative charge at its dome.

    26. What can you observe?

    27. The metal-coated ball is first attracted to the dome and it is repelled after touching the dome. Fun with electric charges

    28. Fun with electric charges

    29. Fun with electric charges

    30. Fun with electric charges

    31. Example 2 The hairs of a girl stand on-ends when she touches the dome of Van de Graaff generator.

    32. Example 2

    33. Example 2

    34. Example 2

    35. Q1 Touching at which of the...

    36. Q2 How can you avoid getting...

    37. Q3 Why petrol tankers... Why petrol tankers usually have metal chains at the back?

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