1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
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: Curent Electricity Doubt PLEASE HELP

  1. Sep 2, 2009 #1
    Curent Electricity Doubt!! PLEASE HELP!!

    1. The problem statement, all variables and given/known data
    I did not understand one thing.. If it is given that a wire has a current 'i', then why do we say (in applications of laws such as biot savart law) that the current in a small element of the wire is also 'i', that is the same current that passes through the whole conductor.

    2. Relevant equations
    can someone explain this. i got really confused on this one.

    3. The attempt at a solution
    I thought we should take curent in the ' dl ' element of the wire as ' di ' and not i. I am wrong. Please Explain, anyone!
    Last edited: Sep 2, 2009
  2. jcsd
  3. Sep 2, 2009 #2
    Re: Curent Electricity Doubt!! PLEASE HELP!!

    Current is [tex]\frac{dQ}{dt}[/tex], the amount of charge which passes through a cross-section of the wire per unit time. This value does not depend on the lenght segment of wire.

    Also, for one segment of wire to have a different current than another causes a buildup of charge, inconsistent with Kirchhoff's junction rule.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook