- #1
Finding Total Resistance in a Circuit for Scientists
- Thread starter jafferrox
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- Resistance
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Discussion Overview
The discussion revolves around finding the total resistance in a specific electrical circuit. Participants explore different methods for calculating resistance based on the arrangement of resistors, including series and parallel configurations.
Discussion Character
- Homework-related
- Mathematical reasoning
- Technical explanation
Main Points Raised
- One participant suggests identifying resistors that share the same start and end nodes to determine if they are in series or parallel, providing a method for calculating total resistance.
- Another participant calculates a total resistance of 17.5 ohms, detailing their step-by-step process of combining resistors in parallel and series.
- Several participants express uncertainty about the configuration of a specific 20 ohm resistor, questioning whether it is in series or parallel with other resistors.
- A later reply emphasizes the importance of viewing circuits as nodes rather than just their physical orientation to aid in understanding the connections.
Areas of Agreement / Disagreement
There is no consensus on the configuration of the 20 ohm resistor, with multiple participants expressing uncertainty. The calculations provided by participants yield different total resistance values, indicating that the discussion remains unresolved regarding the correct total resistance of the circuit.
Contextual Notes
Participants' calculations depend on their interpretations of the circuit diagram, which may not be fully detailed in the discussion. There are also unresolved assumptions regarding the arrangement of the resistors.
- #2
nevermaybe
- 6
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Look at the circuit for what share the same start and end nodes and what don't. Those that do share the same start and end nodes add in parallel and those that don't add in series. So the 2 ten ohm resistors on the very right are in series, but that 20ohm resistor adds in parallel to the total of the 2 ten ohm resistors added in series.
To get you started, the right hand "upper triangle" should look like this...
10 ohms + 10 ohms = 20 ohms
and 20*20/(20+20) = R total
(or.. 1/Rtotal = (1/20) + (1/20))
R total for that very right "upper triangle" being 10 ohms.
To get you started, the right hand "upper triangle" should look like this...
10 ohms + 10 ohms = 20 ohms
and 20*20/(20+20) = R total
(or.. 1/Rtotal = (1/20) + (1/20))
R total for that very right "upper triangle" being 10 ohms.
- #3
nevermaybe
- 6
- 0
From quick rough working.. I got 17.5 ohms for the total of the circuit.
So, starting from right to left... I got.
10 ohms in parallel with 20 ohms.
This gave me 6.666667 ohms in parallel with another 20 ohms
which gave me 5 ohms, which is in series with 20 ohms.
This gives 25 ohms, which is now in parallel with 25 ohms.
This gives 12.5 ohms, which is now in series with the 5 ohm resistor, and totals 17.5 ohms.
So, starting from right to left... I got.
10 ohms in parallel with 20 ohms.
This gave me 6.666667 ohms in parallel with another 20 ohms
which gave me 5 ohms, which is in series with 20 ohms.
This gives 25 ohms, which is now in parallel with 25 ohms.
This gives 12.5 ohms, which is now in series with the 5 ohm resistor, and totals 17.5 ohms.
- #4
- #5
nevermaybe
- 6
- 0
jafferrox said:
np! (Don't quote me as I'm only a third year college student haha, but I do quite well on electrical papers)
That depends, just start from right to left as I outlined in my post previously. And reduce the circuit down resistor by resistor.
That resistor though, is in series with the 5 resistors on the right as they don't share the same start and end nodes because of that 25 ohm resistor.
Last edited:
- #6
jafferrox
- 25
- 0
The answer is right man, thanks heaps for the help :)
- #7
nevermaybe
- 6
- 0
:D
Excellent. I hope you learnt! Make sure you try see circuits as nodes rather than just the way they're orientated.
Excellent. I hope you learnt! Make sure you try see circuits as nodes rather than just the way they're orientated.
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