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Circuit Components-Variable resistors

  1. May 9, 2015 #1
    1. The problem statement, all variables and given/known data
    As contact point Y moves to X, the lamps becomes brighter. Why is this so?

    2. Relevant equations
    R=p (length/Area)

    3. The attempt at a solution

    As Y moves closer to X, length of wire decreases, hence resistance decreases and brightness of lamp increases.

    I am not clear of the concept of brightness of lamp and resistance of wire. Please help, thank you!

    Attached Files:

  2. jcsd
  3. May 9, 2015 #2


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    Homework Helper

    The lamp is in a series circuit with a power supply with a fixed voltage. What would make the light bulb burn brighter?
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