engineering homework

ECE 101

Homework Assignment #6

Due: Week 8, Tues. 2/26/19 *

(20 pts) Two problems on simultaneous equations from the Mathematics for Engineering Applications textbook (remember the textbook?)

1. (14 pts) Complete problem 7-1 just as written. You can (and should) use your calculator to check your work, but you must show the hand calculations clearly worked out using the specified methods for all parts of the problem.

2. (6 pts) Look at the circuit in Figure P7-4. We will use this circuit, but ignore the voltage equations given and the questions asked in the problem. Note that this circuit has three “loops” and define three currents, one in each loop with a clockwise orientation as in the previous problem. Label them left-to-right I1, I2, I3. Ask if this setup is not clear.

This gives the following three KVL equations. You should verify for yourself that these are the correct equations.

30I1 – 20I2 = 10

60I2 – 20I1 – 20I3 = 0

50I3 – 20I2 + 20 = 0

a) Set up these three equations in matrix form. You will have a 3x3 matrix for A.

b) Use your calculator to solve the equations for I1, I2, I3. You don’t have to do any calculations by hand. Give your answers to three significant figures (e.g., 1.23 or 0.456)