Circuit Analysis: Solving Homework Problems in EE

[ryujio85]

Homework Statement

OK well I have this as a small piece of assessment and I am really bad at electrical engineering civil is my major heh.

http://img161.imageshack.us/img161/2461/image1uw1.jpg


1. Find the voltages at A and B (with respect to reference node G) using mesh analysis,
2. Replace subcircuits G-A, A-B, and B-G by their Thevenin equivalents. Hence
find the voltages at A and B (with respect to G), the power dissipated in each
resistor in the original circuit, and the power supplied by each source.
Hint: the power supplied by the current source is about -1.8 watts.
3. Find the voltages at A and B (with respect to G) by using the superposition of
the effects of the three sources.

Homework Equations

KVL, KCL, Mesh analysis, nodal analysis, superposition, thevenin equivelants

The Attempt at a Solution

part 1 - I figured that I have to use mesh analysis to find I1, I2 and I3 and then apply the brach currents in R2 and R4 I used mesh analysis and got values for i1/i2 and i3 but don't really know exactly what to do from there
part 2/3 - I am totally lost

I realize this is a pretty poor start but electrical engineering is not something I've ever dealt with Any help/guidance is much appreciated if someone wated to give me some really specific advice my email is ryujio85@tpg.com.au and my msn is ryanmarshall_85@hotmail.com Id reimburse you for your time if you helped me out at a normal tutor rate.

 

[Astronuc]

One's textbook should cover the application of Thevinin's theorem.

See if this helps - http://www.allaboutcircuits.com/vol_1/chpt_10/8.html


Also - http://www.allaboutcircuits.com/vol_1/chpt_6/index.html


The power dissipated in a resistor is simply the product of the voltage drop, V_R across that resistor and the current through the resistor, which is also V_R²/R or alternatively I²R.

 

[piercas]

I understand that not everyone may have a strong background in electrical engineering. However, it is important to approach this problem with a logical and systematic approach.

Firstly, it is important to carefully examine the circuit and identify the different components and their values. This will help in applying the relevant equations and techniques for solving the problem.

In part 1, you correctly identified that mesh analysis should be used to solve for the currents in the circuit. Remember to apply Kirchhoff's Voltage Law (KVL) and Kirchhoff's Current Law (KCL) to each mesh to determine the equations needed to solve for the currents.

In part 2, you are asked to replace subcircuits with their Thevenin equivalents. This involves finding the equivalent resistance and voltage for each subcircuit. Once you have these values, you can use them to solve for the voltages at A and B, as well as the power dissipated in each resistor and the power supplied by each source.

In part 3, you are asked to use superposition to find the voltages at A and B. This involves considering the effects of each source separately and then adding them together to get the final voltage values.

I understand that this may be a challenging problem for someone with a limited background in electrical engineering, but with careful analysis and application of the relevant equations and techniques, it is possible to arrive at a solution. I would recommend seeking help from a tutor or classmate who may have a stronger understanding of the subject. Additionally, there are many online resources and tutorials available that may be helpful in understanding the concepts and solving similar problems. Good luck with your assessment.