**Most of you probably know about Ohms Law or
have heard it mentioned at some seminar, how often do you use it in
your diagnostic procedures? Some of you may laugh at the mention of
it, or may not even know what it means. It can be a powerful tool,
and help you in electrical diagnostics.**

**One Volt of electrical pressure will push
one Ampere of electrical Current through one Ohm of electrical
Resistance.**

**You have probably seen the circle divided
three ways with the symbols "I" for current, "V" for volts, and "R"
for resistance, I will not confuse you with that here, just tell you
the formulas.**

**If you know two of any of the three values,
the third can be found with simple math:**

**If you have amps and ohms, multiply amps
times ohms to get voltage. (E = I X R)**

**If you have volts and ohms, divide volts by
ohms to get amps. (I = E / R)**

**If you have volts and amps, divide volts by
amps to get ohms. (R = E / R)**

**"I" stands for Intensity or electrical
current. ***flow*

**"E" stands for volts or EMF.
(ElectroMotiveForce) ***pressure*

**"R" stands for Resistance or ohms.
***resistance*

**All this was discovered by a German
scientist named Gustav Kirchhoff, who found that, the sum of the
voltage drops across all resistances in a circuit must equal the
voltage of the source. Also that, the sum of the currents flowing
into any point in a circuit equals the sum of the currents flowing
out of the same point.**

**Some of you may find this a bit confusing,
others may understand it perfectly well, lets put it to practical
use.**

**To find the motor resistance in this
****case
study****, divide volts by amps,
12.6Volts/20.43Amps=0.61 Ohms or six tenths of an ohm. The new motor
pulled 10.95Amps, so 12.6Volts/10.95Amps=1.15 Ohms**