Chapter
17 & 18
Direct
Current & Circuits
Example
18-7 Solution
First
since there is a capacitor in the circuit we need to look at
that part first. When it says steady-state there is no current through
that part of the circuit so we can ignore it.
We
have two nodes again at c and f. Both nodes produce
identical equations so we will use the one at point c:
(1) 
Lets
use loops defcd and cfgbc for the other two equations:
(2) defcd 
(3) cfgbc 
If
we solve equation (1) for we
get and
then substitute this into equation (3) and simplify:
(4) 
Then
subtracting equation (4) from equation (2) will eliminate ,
then solve for :

Using
equation (3) and equation (1) gives:
=
1.38 A and =
1.02 A
(b)
We can apply the loop rule for the capacitor loop to find the
potential difference across the capacitor.


because the
charge on the capacitor is:

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