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Ohm’s law, Kirchhoff’s current law, Vi r – Cub Cadet Z-Force S Series User Manual

Page 119

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Electrical System

113

Ohm’s Law

Ohm’s Law relates voltage, amperage, and resistance. It states that voltage is the product of resistance times

current.

• It is written as V = I x R.

• In simplest terms, it goes like this:

It takes 1 volt to push 1 amp through a resis-
tance of 1 ohm (1 = 1 x 1).

• This equation can be rearranged using algebra to

solve for any one variable.

• Those who were traumatized by algebra can rep-

resent Ohm’s law as a triangle. When using the tri-
angle, cover the value to be found, and the two
values left exposed signify how to obtain that
value. See Figure 7.35.

• As an example if the “R” is covered, the “V” is over

the “I” which means “V” divided by ”I” will solve for
the covered letter “R” (V/I = R).

• If the “V” is covered, “I” and “R” are exposed on the

same line, meaning that the product of “I” times “R”
will solve for the unknown “V” (I x R = V).

Kirchhoff’s current law

Kirchhoff’s current law deals with nodes. Nodes are the junction of two or more wires or the junction of a wire to

a component.

Kirchhoff’s current law states that what ever current goes into a node must come out.

As an example: Three wires are connected with a wire
nut. One wire has 5 amps going into the connection:

• The sum of the currents coming out of the other

two wires must equal 5 amps. That could be 3
amps in one wire and 2 amps in the other or it
could be 2.5 amps in each wire, but the total com-
ing out must be the same as the current going in.
See Figure 7.36.

Figure 7.35

V

I

R

Figure 7.36

5 Amps

3 Amps

2 Amps

Node