Equivalent resistance of simple circuit

AI Thread Summary
The discussion focuses on finding the equivalent resistance of a complex circuit. Participants highlight the importance of identifying series and parallel resistors, suggesting that symmetry can simplify the problem by allowing the removal of certain resistors. One user successfully solves the problem using Y-Delta transforms, which can systematically reduce the network to a single resistance. The symmetry argument is acknowledged as clever but not necessary for solving the circuit. Overall, understanding circuit symmetry and applying Y-Delta transforms are key strategies for determining equivalent resistance in complex circuits.
nil1996
Messages
301
Reaction score
7

Homework Statement


Find the equivalent resistance of the following circuit.
http://img706.imageshack.us/img706/9644/zkz7.png


Homework Equations


none


The Attempt at a Solution


I am not able to find out which are resistors are in series and are in parallel.Is there any special method to solve these problems?
 
Last edited by a moderator:
Physics news on Phys.org
Think about drawing this in a different way so you can see the parallel and series resistors more clearly
 
Use the symmetry of the circuit. There is a plane about which the circuit is symmetrical. By symmetry all the points in this plane are equipotential. Armed with this information you can simplify this circuit by removing a resistor as no current flows through it.
 
consciousness said:
Use the symmetry of the circuit. There is a plane about which the circuit is symmetrical. By symmetry all the points in this plane are equipotential. Armed with this information you can simplify this circuit by removing a resistor as no current flows through it.

thanks a lot!:thumbs:
i solved the problem
 
This network is an example of non-parallel/non-serial. The direct method is to use the Y-Delta transforms: http://en.wikipedia.org/wiki/Y-Δ_transform

Then you can slowly reduce the network to a single resistance. The symmetry argument is very clever ... but the transforms work even when you are not feeling clever!
 
Thread 'Voltmeter readings for this circuit with switches'
TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...
Thread 'Struggling to make relation between elastic force and height'
Hello guys this is what I tried so far. I used the UTS to calculate the force it needs when the rope tears. My idea was to make a relationship/ function that would give me the force depending on height. Yeah i couldnt find a way to solve it. I also thought about how I could use hooks law (how it was given to me in my script) with the thought of instead of having two part of a rope id have one singular rope from the middle to the top where I could find the difference in height. But the...
Back
Top