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: Phasor form of an E field

  1. Dec 8, 2013 #1
    If I am given an E field E = uniti Asin[w(t-z/c)+pi/4].
    Is the phasor form = unit i Aexp(j pi/4) or unit i Aexp(-j(wz/c - pi/4) ?
  2. jcsd
  3. Dec 8, 2013 #2

    rude man

    User Avatar
    Homework Helper
    Gold Member

    The phasor of a function (wave) containing variables other than time, in this case distance z, is I believe represented by a function including z but not t.

    So the phasor of A cos(wt - kz) would be A exp(-jkz) as the time function is Re{A exp j(wt - kz)}. The exp(jwt) is left out of the phasor expression since in any equation using phasors that term cancels out. At least that's been my experience with e-m wave phasors.

    So if the time function is A sin(wt - kz + θ), what do you think the phasor is?
    Hint: change your time function to read A cos(wt - kz + ψ).
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted