1. Not finding help here? Sign up for a free 30min 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!

Current across resistor and inductor

  1. May 2, 2007 #1
    1. The problem statement, all variables and given/known data
    I have a resistor and an inductor in series. The current across each is the same, correct? I want to know if I can use Ohm's Law to solve for current across the inductor if I know the Voltage and inductive reactance. Basically, does I = V/X_{L} ?


    2. Relevant equations

    V = IR
    I = V/R

    does I = V/ X_{L} ?

    3. The attempt at a solution
     
  2. jcsd
  3. May 2, 2007 #2

    HallsofIvy

    User Avatar
    Staff Emeritus
    Science Advisor

    ??What do you mean by X_{L}? I can guess that V is the voltage drop, I the current and R the resistance. Is X_{L} the inductance? If so then, no, the voltage drop over an inductance is NOT given by the same equation as for a resistance. Surely you have that formula in your text?
     
  4. May 2, 2007 #3
    X_{l}

    by this i mean inductive reactance...sorry, it's tex syntax for X with L as a subscript. i have the habit of writing all my mathy stuff in latex syntax
     
  5. May 2, 2007 #4

    SGT

    User Avatar

    Yes, [tex]I = \frac{V_L}{X_L}[/tex]
    Notice that [tex]X_L[/tex] is dependent of the frequency of [tex]V_L[/tex]
     
  6. Feb 21, 2009 #5
    Forget the problem for a minute, first lets clear up that current isn't across anything. Current flows through and voltage is established across. Like fingers on a chalk board.:cry:
     
  7. Feb 21, 2009 #6
    If those 2 elements are in series (the resistor and inductor) and connected to a voltage source, the current through all elements will be given by:

    I = VS / (R + XL)


    If the voltage you are talking about is the voltage across the inductor, then yes, the current through all elements will given by:

    I = VL / XL
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Current across resistor and inductor
Loading...