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Homework Help: Confused by lecture notes (Electrical)

  1. May 18, 2012 #1
    So we're converting these currents from phasor to time domain with ω=4.

    I understand I1, but not how the lecturer got I2, is this an error with the notes?

    We have these phasors:

    Which are converted to this time domain (respectively):

    Any help is much appreciated.
  2. jcsd
  3. May 18, 2012 #2


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    Staff: Mentor

    Hmm. I2 doesn't look correct to me for a couple of reasons. First, if the angle had been adjusted by adding 360°, giving -160.6 + 360 = 199.4°, then the result should show it as a positive phase angle, not negative. Second, the convention is to specify phase angles in the range +/- 180°, and 199.4° falls outside this range.
  4. May 19, 2012 #3


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    Staff: Mentor

    Check I2. Possibly it was given as 3.254 ∠160.6°
    and lecturer is converting all angles to lagging.
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