Please help Circuit analysis (Thevenin voltage and internal resistance)

[Odyssey]

URGENT! Please help! Circuit analysis (Thevenin voltage and internal resistance)

Hi guys,
I am really stuck on this portion of my lab and it's due tomorrow! Please help!

I have two questions:
The first deals with the diagram from the left of the attached picture. I have to prove that RI (internal resistance of the meter movement) is equal to (RS)(RP)/(RS-RP). I tried reducing the circuit through circuit analysis (Rs = R1+R2+... and 1/Rp=(1/R1)+(1/R2)+...) but it doesn't work. Please give me some pointers, thank you.

The second question is about the circuit on the right. I have to find the Thevenin voltage for this circuit. I know this is equal to the open circuit voltage which I measured to be 0.790V in the lab. I found the Thevenin resistance to be RTH=1,500 Ohms by circuit analysis. Please give me some ideas on how to solve for VTH, thank you!

 

[Mindscrape]

Don't know what the circuit looks like, but the procedure for finding the look in resistance is to turn off all your sources. Open circuit your current sources and short circuit your voltage sources.

You can solve for the Thevenin voltage by finding the short circuit current at the load terminals.

 

[kyle8921]

Hi there,

I understand that you are in a time crunch and need help with your circuit analysis lab. It is important to remember that circuit analysis can be a complex and time-consuming process, so it is important to approach it with patience and a clear understanding of the concepts involved.

For your first question, it seems like you are on the right track by using the equations for series and parallel resistors to reduce the circuit. However, it is important to also consider the meter movement as a component in the circuit, and take into account its internal resistance. I would suggest looking into the concept of equivalent circuits, where the meter movement and its internal resistance can be represented by a single resistor in series with the rest of the circuit. This will make it easier to solve for the internal resistance RI.

For your second question, you are correct in finding the Thevenin resistance by using the circuit analysis equations. To find the Thevenin voltage, you can use the Thevenin theorem, which states that the open circuit voltage is equal to the Thevenin voltage. In other words, you can use the 0.790V measurement as your Thevenin voltage. Alternatively, you can also use the voltage divider formula, where VTH = Vsource x (RTH/(RTH+RL)). In this case, RL would be the load resistor in the circuit.

I hope this helps and good luck with your lab! Remember to approach circuit analysis with a clear understanding of the concepts and take your time to solve it systematically. Don't hesitate to reach out for further clarification.