PRACTICAL MATLAB® FOR ENGINEERS PRACTICAL MATLAB

Direct Current and Transient Analysis 155

MATLAB Solution

>> R = [-1 1 1;10 5 0;0 -5 30];

>> V = [0;10;0];

>> I = inv(R)*V; % Solves for the loop currents

>> Result = [I(1) I(2) I(3)];

>> % Results are printed

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

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

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

>> disp(‘ The currents I1, I2, I3 are:’);

>> disp(Result)

>> disp(‘ amp. amp. Amp.’);

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

************************************

**********R E S U L T S************

************************************

The currents I1, I2, I3 are:

0.7000 0.6000 0.1000

amp. amp. amp.

***********************************

Example 2.14

Solve for the loop currents I 1 and I 2 shown in the circuit diagram of Figure 2.53

(Example 2.13) by using

i. The matrix operation I = R\V

ii. The symbolic method

iii. Compare the results of i and ii with the solution obtained in Example 2.13

ANALYTICAL Solution

The loop equations are

For loop# I, (^15) I 1 − (^5) I 2 = 10
For loop# II, − (^5) I 1 + (5 + 10 + 20) I 2 = 0
FIGURE 2.52
Network of Example 2.13.
5 Ω
10 V
10 Ω
−

• I 2
  10 Ω
  20 Ω
  I 1
  Loop # 1 Loop # 2
  I 3