# Need help solving resistor network problems

this isnt so much of a homework question . Im having trouble with identifying and calcultaing effective resistence for parallel or series connected resistors particularly ones that are very complex to even understand whats going on .... I did look through various websites and books looking for answers but ended up finding nothing .... my book listed 2 examples of the kind but these were poorly explained :(

this is not so much of a homework problem, but ive been having trouble solving these questions (2 days in a row )..... are there any ways or say tips i could use to tackle these problems ??? websites ive missed , books i might have to glance through ?? (but mainly helpful websites ...)

thanks in advance .
junior

## Answers and Replies

berkeman
Mentor
When you can, use series & parallel combinations of resistors to simplify the circuit. Once you're done with the simplifications, write the KCL (or KCL) equations for the nodes, and solve for the node voltages.

the problems Im dealing with right now dont even mention emfs or pds .... they say something to the effect " Find the effective resistence between x and y " ... and in between x and y lies a jungle of resistors . I can't even comprehend how theyre put together ...

berkeman
Mentor
Well, it's physical, so it's solvable. Can you post a copy of the drawing?

there are many of these problems ..... I just want to learn how to do this .... errm if ud do it for me Ill get off the hook pretty easy

Can u just tell me how ud go about solving these ??? may be tips/pointers or something like that

teach a man how to fish blah blah proverb comes to mind :)

.... will i have to draw this one on mspaint ???? really .... !!
Im not jokin around ..... i googled for these problems , nothin came up ....

berkeman
Mentor
Sometimes you can use a symmetry in the problem to help out. Like with R-2R ladders used in DAC circuits, for example. Either you can simplify with parallel-series combinations, or use a symmetry, or you just have to brute force it with KCL. If all the resistors have the same value or related values, that generally helps with the symmetry arguments.

My physics book doesnt even go as far as to properly describe how to do these .... Ill be damned if i ever open that book again !!!!!!!

anyways ur not getting through ... i have a thick skull !!!!

thanks.