[Tutor] Re: complex numbers: j vs. i

Blake.Garretson@dana.com Blake.Garretson@dana.com
Mon, 26 Aug 2002 08:54:35 -0400


Kirk Bailey Wrote:
>CAPITAL 'i' is current.
>'I'
>I=E/R (ohm's law)
>'i' is used for indexing. hmmm. and here I have idle open.
>
>>>>
>>>> i="index"
>>>> I="'current'"

Um, no.  Not true.  In engineering circles (especially electrical
engineering), I/i is always current, regardless of case.  Capital I is
often used when writing equations, but lower case i is also used just as
often, and is probably more frequently seen when diagramming Kirchhoff's
current law.

Since i is sacred, j was substituted for i in complex numbers.  Electrical
engineering calculations favor complex numbers because you can represent
sinusoidal signals as complex numbers and eliminate the need for solving
differential equations.

Blake Garretson