Ohm's Law - Casio fx-7400G PLUS Booklet

EE-2 Ohm's Law
Ohm's law deals with the relationship between current, voltage, and resistance.
The following expressions express this relationship, when I is current, R is resistance, and E is
voltage.
I = E / R
k Proportional Expression
The proportional expression is
x y
causes the value to double or triple.
The following is the graph of the relationship between
The a variable in the proportional expression has a linear slope. The larger it value, the
greater the slope of the line is.
y = 0.5x
The graphs of
We can use these graphs to obtain the value of
passes through a point where
is:
9 = a
a = 3
R = E / I
y ax
= , where
y
y = 2x
and are shown below.
y
4
3
2
1
0 1 2
y
= 9 and
3
This means that the linear expression is
a
is the constant of proportion. Doubling or tripling
x and y .
y=ax
y = 2 x
3 4 5 6 7
a
. If the proportional expression graph
x
= 3 (coordinates (3, 9)), for example, the value of
– 20 –
E = IR
x
y = 0 . 5 x
x
y = 3x.
a