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    When two insulating objects are rubbed together, how do you know which object the electrons leave and go onto the the other object? Do all insulators have electrons on them?
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    (Original post by Daydreamer3)
    When two insulating objects are rubbed together, how do you know which object the electrons leave and go onto the the other object? Do all insulators have electrons on them?
    They will tell you which material becomes positively charged and which becomes negatively charged. You should be able to use this to deduce the net electron flow between the materials; the insulator that has become positively charged has had a net loss of electrons, while the one that has become negatively charged has had a net gain of electrons.

    You can think about it intuitively, because electrons are negatively charged. So the insulator with the negative charge must have a surplus of negative charges, i.e. electrons, while the object that becomes positively charged must have less of these negative charges.

    I'm not sure what you mean by "do all insulators have electrons on them?".
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    (Original post by crashMATHS)
    They will tell you which material becomes positively charged and which becomes negatively charged. You should be able to use this to deduce the net electron flow between the materials; the insulator that has become positively charged has had a net loss of electrons, while the one that has become negatively charged has had a net gain of electrons.

    You can think about it intuitively, because electrons are negatively charged. So the insulator with the negative charge must have a surplus of negative charges, i.e. electrons, while the object that becomes positively charged must have less of these negative charges.

    I'm not sure what you mean by "do all insulators have electrons on them?".
    Ohh okay thank you!
    And this is out of context but in a series circuit, if there are two cells with 12V each what would the total voltage be? Would it be 24V or 12V?

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    So I am basically confused with this diagram as to how why does one only have 12V in total even though there are two cells with 12V each...?

    (I have just realised that the second image is a parallel circuit, hence why)
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    Is this series or parallel?
    And if the circuit was just the cell and one resistor in series, then the current was 0.2A. Why would it be 0.4A is the circuit was then set up like that ^^?.?
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    The two resistors are in parallel. When resistors are in parallel, the total resistance decreases. Therefore you would expect more current in the circuit.
    This video will help your understanding of the subject:
    https://www.youtube.com/watch?v=VQuM2QS8Zhk
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    (Original post by Mo H)
    The two resistors are in parallel. When resistors are in parallel, the total resistance decreases. Therefore you would expect more current in the circuit.
    This video will help your understanding of the subject:
    https://www.youtube.com/watch?v=VQuM2QS8Zhk
    Ohh okay thank you! I just dont understand how its parallel because it looks like series too me lol
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    Oh I see. You can tell the resistors are in parallel because the current has to split at a junction in order to reach them both. Any time there is more than one path for the current to flow, it's got to be a parallel circuit.
 
 
 
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