Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Number of Wires & Cross-Sectional Area

  1. Sep 20, 2011 #1
    Hi there, I'm a student in high school.
    I'm quite new to the forum. Please forgive my mistakes.

    The problem statement, all variables and given/known data
    My question is related to electricity, more specifically the factors affecting resistance in a wire. I know that resistance is inversely proportional to the cross-sectional area of the wire.

    Does the number of wires represent the cross-sectional area of the wire?

    Relevant equations
    The circuit diagram is in the attachment.
    I came across an experiment which describes that by changing the number of wires (ie. changing the number of eureka wires), we actually change its cross-sectional area.

    The attempt at a solution
    However, doesn't adding the number of wires make it become a parallel circuit?

    Help to clarify please?

    Attached Files:

  2. jcsd
  3. Sep 20, 2011 #2
    By adding more wires between points x and y, you are increasing the cross section of wire between these points. Between x and y, these wires are in parallel (so there is less current flowing through each wire. Using V=IR where V = const you can see that R reduces).
  4. Oct 2, 2011 #3
    Alright. Thanks!!
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook