PRACTICAL MATLAB® FOR ENGINEERS PRACTICAL MATLAB

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