PRACTICAL MATLAB® FOR ENGINEERS PRACTICAL MATLAB

Direct Current and Transient Analysis 159

Example 2.16

Create the script fi le current_voltage that returns the currents I 1 , I 2 , I 3 , I 4 , I 5 , I 6 , I 7 , I 8 , and

the voltage Vab shown in the circuit diagram of Figure 2.59 (used in Figure 2.54), given

the fact that the current I = 3 A through the 7 Ω resistor.

MATLAB Solution

% Script file: current _ voltage

clear;clc;

I = 3;

Vyb = 3*5; % from Figure 2.54a

Vxb = 12*3; % from Figure 2.54b

I1 = Vyb/15;

I2 = Vyb/10;

I3 = Vyb/30;

I8 = Vxb/6; % from Figure 2.54c

I4 = (4/16)*I8; % current divider

I5 = (12/16)*I8;

I6 = I8/2;

I7 = I6;

Vab = (I+I8)*5; % from Figure 2.54e

result = [I1 I2 I3 I4 I5 I6 I7 I8];

disp(‘**********************************’);

disp(‘**********R E S U L T S**********’);

disp(‘**********************************’);

disp(‘ ‘);

disp(‘ The currents I1 I2 I3 I4 I5 I6 I7 and I8 (in amps) are given by:’);

disp(result’);

disp(‘*********************************’);

disp(‘The voltage Vab is:’); disp(Vab); disp(‘volts’)

disp(‘*********************************’);

FIGURE 2.59

Network of Example 2.16.

15 Ω

7 Ω

12 Ω

1 Ω

X

4 Ω 6 Ω

4 Ω

a b

Y

2 Ω

I 1

I 2

I 3

I 7

I 6

I 5

I 4

I = 3 A

10 Ω

30 Ω

I 8