Direct Current and Transient Analysis 217
P.2.27 For the circuits shown in Figure 2.123 evaluate R by
a. Writing a MATLAB program using the standard circuit analytical techniques
b. Writing a MATLAB program that computes R by using the relation of P.2.26
given by
RR
GR
nn
iii
n
i
n
1
1 2211
11
∑∑ for 3 and^4
P.2.28 Draw the possible circuit diagrams for the electrical network defi ned by the follow-
ing set of mesh equations:
a. 20I 1 − 5 I 2 = 10
− 5 I 1 + 10 I 2 = − 7
b. 10 = 6 I 1 − 2 I 2 − 3 I 3
− 6 = − 2 I 1 + 6 I 2 − 4 I 3
5 = − 3 I 1 − 4 I 2 + 12 I 3
c. Using MATLAB, solve each system (a and b) that consists of the set of loop
equations
P.2.29 Verify that the equivalent resistance (between terminals a and a’) of the circuit of
Figure 2.124 is given by
R
RRR R RRR R RR RR R
RRRR
123 4 3 41 2 51 32 4
123 4
() ()()( )
()( )()RRRRR123 45
P.2.30 Evaluate the equivalent resistance between terminals a and a’, of the circuit dia-
gram shown in Figure 2.124, by applying the following techniques or procedures:
a. Connect an arbitrary voltage source V across aa’, solve for the current I, and then
evaluate Raa’ = V/I
FIGURE 2.124
Network of P.2.29.
I
R 1
R 2
R 3
R 4
R 5
a a′
FIGURE 2.125
Network of P.2.31.
R 1 R 2
R 2 R 1
R 3
a a′
I