Biomedical Engineering Reference
In-Depth Information
In general, if a circuit contains
resistors in series, the voltage divider rule gives the volt-
age across any one of the resistors,
N
R
i
,as
R
i
V
i
¼
V
s
ð
9
:
16
Þ
þ
R
þ
R
N
R
1
2
Current Divider Rule
The current divider rule allows us to easily calculate the current through any resistor in
parallel resistor circuits. Consider finding
I
2
in the parallel circuit shown in Figure 9.19,
R
R
2
R
1
þ
R
2
1
where
R
EQ
¼
. Accordingly,
I
2
¼
V
s
R
2
and
R
1
R
2
R
1
þ
R
2
V
s
¼
I
yielding after substituting
V
s
1
R
2
I
2
¼
I
1
R
1
R
1
þ
2
In general, if a circuit contains
resistors in parallel, the current divider rule gives the
current through any one of the resistors,
N
R
i
,as
1
R
i
I
i
¼
I
ð
9
:
17
Þ
1
R
1
þ
1
R
2
þ
1
R
N
I
I
1
I
2
+
−
V
S
R
1
R
2
FIGURE 9.19
Current divider rule circuit.