[Circuits] Finding maximum power

[ainster31]

Homework Statement

a. Find the Thevenin equivalent circuit across R_L.
b. What is the value of R_L for maximum power?
c. Calculate the maximum power that can be transferred to the resistor R_L.

Homework Equations

The Attempt at a Solution

[strike]a. R_th=2.88 ohm
b. R_L=2.88 ohm
c. P=154.3 mW[/strike]

Edit: looks like I found an error. Here is my second attempt:

a. R_th=2.933 ohm
b. R_L=2.933 ohm
c. P=150.8 mW

I have a test upcoming and we were given this as a practice question. Unfortuantely, there is no answer so I don't know if I it is correct or not. Can anyone let me know if my answers are right? I used MultiSim to check the answers for my other practice questions and I found mistakes. I can't use MultiSim to check this one.

This is the other similar problem that I need to make sure I have done correctly: http://i.imgur.com/g2JaZXO.png

My answer: P=69.4 mW

 

[NascentOxygen]

Had you provided your working, someone may have looked over it to see whether the approach was right.

A Thévenin equivalent requires a voltage source and a resistance.