midterm - MAE140 Linear Circuits Fall 09 Midterm November...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: MAE140 - Linear Circuits - Fall 09 Midterm, November 10 Instructions (i) This exam is open book. You may use whatever written materials you choose, including your class notes and textbook. You may use a hand calculator with no communication capabilities (ii) You have 70 minutes (iii) Do not forget to write your name, student number, and instructor B +- 10 V 0.5 A 10 40 20 10 Ω Ω Ω Ω A (a) Question 1. A v S i S B D C R 2 R 4 R 3 R 1 i 1 i 2 (b) Question 2. Figure 1: Circuits for questions 1 and 2. 1. Equivalente Circuits Part I [4 points] Use source transformations and association of resistors to find the Thevenin equiva- lent to the circuit in Fig. 1(a) as seen from terminals A and B. Part II [4 points] A classmate was arguing with you that one would “extract” the most power out of this circuit by connecting a very small resistance between terminals A and B. You argued that he/she was wrong and that a 20 Ω resistor would be a better choice. Who is right and why? Hint #1: Don’t complicate: all you need to do is compare the two options! Hint #2: Use the Thevenin equivalent computed in Part I to answer the question. Solution: Part I: A possible series of source transformations is shown here: 10 V +- +- 10 V 40 20 Ω Ω A B 20 Ω (+ 1 point) 20 V +- 40 40 Ω Ω A B Ω 40 Ω A B 0.5 A 40 (+ 1 point) 0.5 A 20 Ω A B (+ 1 point) Ω +- A B 10 V 20 (+ 1 point) Part II: Let’s investigate the two scenarios. In the case of a small resistance, say R = Ω , using the Thevenin equivalent and voltage division we have that...
View Full Document

This note was uploaded on 05/27/2010 for the course MAE MAE140B taught by Professor Linearcircuit during the Spring '09 term at UCSD.

Page1 / 6

midterm - MAE140 Linear Circuits Fall 09 Midterm November...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online