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    Hey!

    Im currently studying the CIE Physics AS Level Course.

    Ive got one doubt in the Electric Fields Topic though!
    For example,
    Questeion: At a certain point in an electric field, the strength is 5 KN/C downwards.
    Find the force on an electron placed at that point.

    So we use the Formula E= F/Q

    What I doubt in, is if we have to use the Positive value of Q (that is the elementary charge, 1.60x10^-19) or the negative one, since electrons are negative.

    Thanks in advance!
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    The direction of the electric field is by convention the direction of the force on a unit positive charge; so the force on an electron will be in the opposite direction.
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    Ah so if the Question said 5 KN/C upwards, then we would use the negative Charge?
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    If the question says the field is downwards, then
    -the force on a positive charge is downwards
    -the force on a negative change (like an electron) is upwards

    The formula gives the magnitude of the force.
 
 
 
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