Thevenin's equivalent circuit problem

  • Thread starter Thread starter backstance
  • Start date Start date
  • Tags Tags
    Circuit Equivalent
AI Thread Summary
The discussion focuses on using Thevenin's theorem to find the current in a 3-ohm resistor within a parallel branch of a circuit. The original poster expresses doubt about the applicability of Thevenin's theorem, suggesting that it only works for series components and that a cut cannot be made across terminals A and B. They propose that Norton's equivalent circuit might be necessary to solve the problem instead. Other participants offer encouragement and suggest reviewing similar circuits for guidance. The conversation highlights the challenges of applying Thevenin's theorem in this specific scenario.
backstance
Messages
14
Reaction score
0

Homework Statement


use thevenin's theorem to find the current in the 3 ohm, parallel branch, resistor

http://img217.imageshack.us/img217/909/img0267cc7.jpg

Homework Equations


Thevenin equivalent circuit, voltage divider rule

The Attempt at a Solution



I don't think its possible, since thevenin's theorem ends up with a voltage source and a resistor in series, you can only find currents and voltages in components that are in series. In this circuit there is nowhere to make the cut and split the circuit across terminals A and B. Normally you'd need Norton's equivalent circuit to find the current in the 3ohm resistor. Am I right, or is there actually a solution using thevenin's?
 
Last edited by a moderator:
Physics news on Phys.org
backstance said:

Homework Statement


use thevenin's theorem to find the current in the 3 ohm, parallel branch, resistor

http://img217.imageshack.us/img217/909/img0267cc7.jpg


Homework Equations


Thevenin equivalent circuit, voltage divider rule


The Attempt at a Solution



I don't think its possible, since thevenin's theorem ends up with a voltage source and a resistor in series, you can only find currents and voltages in components that are in series. In this circuit there is nowhere to make the cut and split the circuit across terminals A and B. Normally you'd need Norton's equivalent circuit to find the current in the 3ohm resistor. Am I right, or is there actually a solution using thevenin's?

Could anyone solve this problem?
 

Attachments

  • Circuit1.PNG
    Circuit1.PNG
    21.8 KB · Views: 502
Last edited by a moderator:
any ideas? any help would be appreciated, thanks!
 
http://www.allaboutcircuits.com/vol_1/chpt_10/8.html
try and study it from the url. The circuit is quite the same as yours.
 
thanks for that, useful!
 
ur most welcome! :D
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top