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Homework Help: How to determine the position of the slider on a potentiometer

  1. Jul 1, 2012 #1
    1. The problem statement, all variables and given/known data

    This circuit shows a 10Kohm potentiomiter with a 5Kohm load.

    determine the position of the slider on the 'pot' when the voltage acreoss points 'xx' is 3V

    ok so the 10K resistor is a potentiometer which is a variable resistor, so what they are asking when they say the position of the slider is what value is the 10Kohm resistor actually set to, is that right??

    I understand that I need to split the 10Kohm resistor in to 2 like i have done on FIG2

    I also know that both resistors make 10K ohms.

    I am assuming that is the slider was in the middle each resistor would have 5KOHM, therefore is it was a quarter of the way up one resistor would be 2.5K and the other would be 7.5KOHM

    So what I need to find is the value of R1 and R2.

    So what formula do I need to use for this?

    Thanks a lot,


    Attached Files:

  2. jcsd
  3. Jul 2, 2012 #2


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    Staff: Mentor

    Hi. Position of the slider can be expressed as a fraction (or a percentage) of the total track resistance, i.e., express R2 as a percentage of the total R1 + R2.

    You don't need a formula; you apply Kirchoff's Laws. Note that the current through R1 splits and some goes through R2 and the rest through the load.
    Last edited: Jul 2, 2012
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