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Current across resistor and inductor

  • Thread starter verbose
  • Start date
  • #1
verbose

Homework Statement


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} ?


Homework Equations



V = IR
I = V/R

does I = V/ X_{L} ?

The Attempt at a Solution

 

Answers and Replies

  • #2
HallsofIvy
Science Advisor
Homework Helper
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??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?
 
  • #3
verbose
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
 
  • #4
SGT
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
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]
 
  • #5
3
0

Homework Statement


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} ?


Homework Equations



V = IR
I = V/R

does I = V/ X_{L} ?

The Attempt at a Solution

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:
 
  • #6
152
0
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
 

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