How to Find Total Equivalent Resistance in Complex Circuits?

[Juntao]

Ok, this problem is bugging. I have to find the total equivalent resistance.
I have included a picture below. There are numbers to this problem, but I want to figure out how to do this in terms of variables first.

First I added R3 and R4 in series
R34=R3+R4

Then I figured out R234= 1/[1/R2+1/R34]

Next I got R1234 = R1+R234
------- *
Now this is where I got stuck
I know the remaining three resistors are in parallel with each other.
I tried doing 1/[1/R5+1/R1234+1/R6], but that didnt seem to work.

Whats the correct procedure to go about this after the *?

 

[ehild]

Ok, this problem is bugging. I have to find the total equivalent resistance.
I have included a picture below. There are numbers to this problem, but I want to figure out how to do this in terms of variables first.

First I added R3 and R4 in series
R34=R3+R4

Then I figured out R234= 1/[1/R2+1/R34]

Next I got R1234 = R1+R234

This last statement is wrong. R1 is connected in parallel with R234. I redrew your circuit, maybe this helps.

ehild

 

[M98Ranger]

After finding R1234, you can find the equivalent resistance of the remaining three resistors (R5, R1234, and R6) in parallel by using the formula:

Req = 1/[1/R5 + 1/R1234 + 1/R6]

This will give you the total equivalent resistance of the entire circuit. If you are still having trouble, make sure to double check your calculations and also check to see if any of the resistors are connected in a different way (i.e. in series instead of parallel). It may also be helpful to redraw the circuit and label the resistors with their equivalent values to make it easier to visualize.