Maximizing Power Transfer in Circuits: Seeking Help with Homework Statement

In summary, the conversation is about finding the maximum power transferred to resistor R in a circuit. The person is struggling to get the correct answer and is asking for someone to review their work. The equations and attempt at a solution are provided, but the correct answer (903.87 V) is not obtained. The expert points out that the potential decreases across the resistor in the direction of the current and asks the person to check their signs.
  • #1
DollarBill
44
0

Homework Statement


I'm looking for the maximum power transferred to resistor R. I know how to approach the problem, but not getting the right answer and was wondering if someone could just look over my work.
[PLAIN]http://img854.imageshack.us/img854/1412/screenshot20110604at115.png

Homework Equations


V=i*R
i1 -> Far Left Loop, Clockwise
i2 -> Middle Loop, Clockwise
i3 -> Far Right Loop (loop containing the current source and 30 kilo-Ohm Resistor), Clockwise
V1 -> Voltage through current source

The Attempt at a Solution



Only concerned about Vth for now:
[PLAIN]http://img580.imageshack.us/img580/7527/image001tr.jpg

(1) 100 + 10*i1 - 40(i1-i2) = 0
(2) 40(i1-i2) + 22*i2 + V1 = 0
(3) -30*i3 - V1 = 0
(4) i3 - i2 = 0.003v0 = 0.003(40)(i1-i2)

Simplified:
(1) -30i1 + 40i2 = -100
(2) 40i1 - 18i2 + V1 = 0
(3) 30i3 + V1 = 0
(4) 0.12i2 + 0.88i2 - i3 = 0


Vth = V1 = 903.87 V (Which I know isn't right)
 
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  • #2
The potential decreases across the resistor in the direction of the current.

ehild
 
  • #3
Could you be a little more specific? I've checked my signs a few times, but am still having trouble seeing where I messed up.
 
  • #4
You have 100 V potential at the upper left corner of the first loop. Then you follow the current through the 10 kohm resistor. The current flows from the higher potential to the lower one, as the water flows from a hill to the valley. Is the potential higher of lower at the other end of it?

ehild
 
  • #5


I would suggest reviewing your calculations and equations to ensure they are correct. It may also be helpful to double check your units and make sure they are consistent throughout your calculations. Additionally, it may be useful to consult with a classmate or your instructor for further clarification and assistance with the problem.
 

FAQ: Maximizing Power Transfer in Circuits: Seeking Help with Homework Statement

How do I calculate the total resistance in a circuit?

To calculate the total resistance in a circuit, you can use Ohm's Law which states that resistance (R) is equal to voltage (V) divided by current (I). This can also be done by using the formula R = R1 + R2 + R3, where R1, R2, and R3 are the resistances of individual components in the circuit.

What is the difference between series and parallel circuits?

In a series circuit, the components are connected in a single loop, meaning the current has only one path to flow through. In a parallel circuit, the components are connected in multiple branches, allowing the current to flow through different paths. This results in different total resistances and current flows in each type of circuit.

Can I use Kirchhoff's Laws to analyze any circuit?

Yes, Kirchhoff's Laws, which state that the sum of currents entering a node is equal to the sum of currents leaving the node and the sum of voltage drops in a closed loop is equal to the sum of voltage sources, can be used to analyze any circuit regardless of its complexity.

How do I calculate the power dissipated in a circuit?

The power dissipated in a circuit can be calculated using the equation P = I^2 * R, where I is the current flowing through the circuit and R is the resistance. This is known as Joule's Law. Alternatively, you can use the formula P = V * I, where V is the voltage across the circuit and I is the current.

What is the purpose of a circuit diagram?

A circuit diagram is a visual representation of how the components in a circuit are connected and their relationships with each other. It is used to understand and analyze the behavior of a circuit, troubleshoot any issues, and design new circuits. It also allows for easy communication and documentation of circuit designs.

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