Imaginary component

Discussion in 'General Electronics Chat' started by aamirali, Sep 3, 2012.

  1. aamirali

    Thread Starter Member

    Feb 2, 2012
    In real world there is only real parts.
    Then why imaginary is included, I never got this. What its use. Finally even answer is calculated by this.

    Like s=jw.
    +j,-j etc
  2. MrChips


    Oct 2, 2009
    "Imaginary" is not imaginary. It is real, i.e. (x + iy) exist in the real world.
    The word "imaginary" in this context as a mathematical construct is an unfortunate usage of the word.

    So just ignore the usual meaning of the word "imaginary" and get on with it.
    On the same note, negative frequencies are real.
    #12 likes this.
  3. Papabravo


    Feb 24, 2006
    In many areas of electronics there are two things we want to keep track of, magnitude and phase. It might be easier on your cognitive sensibilities to rename the imaginary unit as a rotation operator. Instead of starting with j=SQRT(-1) think of multiplication by j as a rotation by 90 degrees. On top of that, four successive rotations returns you to the original position.

    Finally the algebra of complex numbers matches the behavior of AC electric circuits which require you to keep track of both magnitude and phase. That is all the justification you should require.
    nobody0608 likes this.
  4. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    Do keep trying to get this as it IS useful.

    It's a mathematical term, and like most things mathematical they have no direct connection with reality.

    Don't believe me? Just try to make 1/2 of a piece of paper.

    No matter how carefully you measure and cut it you always end up with two pieces of paper, just smaller then the one you started with.
  5. bountyhunter

    Well-Known Member

    Sep 7, 2009
    It sure is. They should have gotten a better name.

    It is also referred to as the "complex" component which is a better name than imaginary..