I need help deciphering this circuit

EnochHill

Joined Feb 25, 2022
10

Is this 3 parallel 10 ohm plus a 20 ohm resistor? How do I calculate total resistance?

Audioguru again

Joined Oct 21, 2019
6,688
It is obvious that the circuit has no parallel resistors.

Joined Feb 20, 2016
4,471
I wouls start from the right side and work each part out one at a time.

djsfantasi

Joined Apr 11, 2010
9,160
Or start at the left side and break the circuit into equivalent sub-circuits by redrawing the remaining resistor layout. Whichever you understand better.

EnochHill

Joined Feb 25, 2022
10
Can I redraw it as this:

djsfantasi

Joined Apr 11, 2010
9,160

EnochHill

Joined Feb 25, 2022
10
I thought that those three resistors would be in series and would add together.

djsfantasi

Joined Apr 11, 2010
9,160
I thought that those three resistors would be in series and would add together.
Look again…

MrChips

Joined Oct 2, 2009
30,792
You have five 10Ω resistors.

Begin by labeling each resistor, e.g. R1-R5.
Then we can discuss resistors one at a time.

Find two resistors in series and calculate the equivalent resistance.
Find two resistors in parallel and calculate the equivalent resistance.

R1 and R2 above are in parallel.
R3 and R4 are in series.

EnochHill

Joined Feb 25, 2022
10

R4+R5 then R1, R2, and R4-5 are in parallel, but what about R2?

boostbuck

Joined Oct 5, 2017
510
can't you see R3 in there?

MrChips

Joined Oct 2, 2009
30,792
View attachment 261839
R4+R5 then R1, R2, and R4-5 are in parallel, but what about R2?
One step at a time.

Find two resistors in series. Calculate the equivalent resistance. Redraw the circuit. Give the equivalent resistor a new name.

The find two more resistors that can be combined because they are either in series or parallel.

Redraw the circuit after each step.

EnochHill

Joined Feb 25, 2022
10
Sorry, meant R1, R3 and R4-5 in parallel.

MrChips

Joined Oct 2, 2009
30,792
Sorry, meant R1, R3 and R4-5 in parallel.
No. Do what I said. There is no guesswork here.

EnochHill

Joined Feb 25, 2022
10
R4+R5=20 ohm. Now R3 and R4-5 are in parallel so R3-4-5 resistance total is 6.667

MrChips

Joined Oct 2, 2009
30,792
R4+R5=20 ohm. Now R3 and R4-5 are in parallel so R3-4-5 resistance total is 6.667
Redraw the circuit after every step. Then you will see how straight forward it is to solve a problem such as this, without asking for help.

EnochHill

Joined Feb 25, 2022
10
Is this the way?

Attachments

• 1.2 MB Views: 2

MrChips

Joined Oct 2, 2009
30,792
Almost right.

EnochHill

Joined Feb 25, 2022
10
Ok going back to R8.
1/R8=1/10+1/6.6667
R8=1/2.499=4

RT=R1xR8/R1+R8
RT=40/14=2.857

MrChips

Joined Oct 2, 2009
30,792
You are sloppy with your math.
Try again.