> >   Does anyone know why Ohm's law is writtem V=IR (E=IR)
> > instead of I=V/R?  Of course I know they're equivalent.
> > I just wondered why - if I is the dependent variable and V
> > and R are the independent variables - it's basic form
> > isn't I=V/R.

I was always taught R = V/I.

Ohms law is the *definition* of resistance. Unlike many equations which
are approximations, R always equals V/I.

Now, that doesn't mean that R has to be a constant. Semiconductors
obviously have a non-linear V/I curve. Most resistors are made up
of substances which have a highly linear V/I curve. However, they can
be temperature dependent (usually only slightly for good resistors).

Even then, R is found by measuring V and I and then running it through
the equation.

*If* you know that R is approximately a constant, then you can use the
other forms of the equation.
--
D. Jay Newman           !
jay@sprucegrove.com     ! Xander: Giles, don't make cave-slayer unhappy.
http://enerd.ws/robots/ !

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