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: Leading/Lagging and Phasors

  1. May 3, 2008 #1
    1. The problem statement, all variables and given/known data

    Let's say I have
    (1) 6<-9
    (2) 6<189

    I don't have a problem drawing the phasors out, however, I am having a bit of difficulty determining how to 'read' the diagram and tell how one leads/lags the other.

    In the example I've given, I draw out the phasors but when it comes to determining which one lags the other I am a bit confused.

    I can easily find the phase difference (351 - 189 = 162 deg).

    Is there a way I can visually inspect each diagram to determine which one leads and which one lags?
  2. jcsd
  3. May 4, 2008 #2
    Dear jes, -9= 351 its ok but there is 360 degree phase diff (1 full cycle) between them. do u understand my point?

    Suppose, in a perfect circular racing path, u start cycling from 0 degree and round a trip 351 degree and then one of ur frnds starts cycling from -9 degree (means ur 351 degree). At that moment u r lead of ur frnd by 351 degree.

    However, ur answer of the question is:
    Ans: 189 degree leads -9 degree by 198 degree (not 162 degree). (Lets check and discuss with others)
    b fine.
    Last edited: May 4, 2008
  4. May 4, 2008 #3
    Hmm, that's interesting, according to the answer the phase difference should be 162 degrees. I think by convention my book always takes the angle that is less than 180 degrees.

    But anyway, I'm really more interested in figuring out how to look at a phasor diagram and see if one phasor leads/lags the other, I just can't quite tell at this point.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook