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!

Phasor Analysis

  1. Nov 13, 2016 #1
    1. The problem statement, all variables and given/known data
    steady-state current through the loop will be of the form Bsin(1000t +b). What is the phase angle 'b'? in rads

    2. Relevant equations


    3. The attempt at a solution
    600648246d.jpg
    0059633f4b.jpg

    The answer is meant to be 0.46rads/s. However Im getting 9.65x10^-5??
    I have no idea what I did wrong.

    I first converted everything into the phasor domain. Then I used voltage division to get the voltage drop across the resistor. Then I used Ohms Law to get the current through the resistor which is the same as the current through the circuit.
     
  2. jcsd
  3. Nov 13, 2016 #2

    gneill

    User Avatar

    Staff: Mentor

    Check your calculation for the impedance of the inductor. The formula for the impedance of an inductor is not he same as that of a capacitor.

    Don't be afraid to promote j's in the denominator to the numerator. If you have a value like ##1/0.25j##, then this can become ##-4j##.

    You don't need to do any voltage division here. Simply sum up the impedances to find the total impedance. Then apply Ohm's law directly: ##I = E/Z## (where E is the applied potential difference across Z).
     
  4. Nov 13, 2016 #3
    Ah.
    Finally got it. Thank you soo much.
    It says in my lecture notes that inductors can be described be V = jwLI or I = 1/jwL * V
    It says nothing else. How do I know like what to use when? I mean say im converting a 2H inductance into the phasor form, how do I know what to use?
     
  5. Nov 13, 2016 #4

    gneill

    User Avatar

    Staff: Mentor

    ##Z_L = j \omega L##

    ##Z_C = \frac{1}{j \omega C}##
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Phasor Analysis
  1. Phasor analysis (Replies: 1)

Loading...