High school circuit diagram question

AI Thread Summary
The discussion centers around a high school circuit diagram question where the original poster calculated an equivalent resistance of 3 Ohms but found no matching answer option, leading to doubt. Other participants prompted the poster to show their work and emphasized the importance of understanding voltage dividers rather than just focusing on equal currents. The poster eventually realized that equating the output voltage of the top and bottom resistors led to a correct answer of 1.5V, though they initially struggled with the concept. They questioned why the bottom resistances should be lower than the top but later acknowledged the intuitive nature of voltage dividers. The conversation concludes with the poster expressing gratitude for the clarification received.
rayclan
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Hi all. I got 3 Ohms in this question (top current = bottom current hence equivalent series resistance of top 2 and bottom 2 resistors must also be equal), but is that really the right answer? There is no option for 3 Ohms so I am beginning to doubt myself.
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Please use the Homework Help Template the next time you start a schoolwork question thread here. Thank you.

Your answer appears incorrect to me. Can you show the work you did to arrive at it? :smile:
 
berkeman said:
Please use the Homework Help Template the next time you start a schoolwork question thread here. Thank you.

Your answer appears incorrect to me. Can you show the work you did to arrive at it? :smile:

here is my answer: http://imgur.com/a/LJo5Y
 

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rayclan said:
here is my answer: http://imgur.com/a/LJo5Y
What can you tell us about voltage dividers? It's not about equal currents in the two branches, it's about equal voltage dividers... :smile:
 
berkeman said:
What can you tell us about voltage dividers? It's not about equal currents in the two branches, it's about equal voltage dividers... :smile:

ok when i equate the Vout of the top and bottom, i get 1.5V. that is the correct answer but it doesn't make sense in my head. why should the bottom resistances be lower than the top? using the water pressure analogy, wouldn't more electrons want to flow from the 2 ohms to the 3 ohms than R ohms to 4 ohms because they encounter less resistance there than the 4 ohms?

edit: what i am also trying to say is, is there another way to do this aside from using the concept of voltage dividers?

edit: hangon i get it now. thanks very much. I've never seen voltage dividers ever in my life before but it is intuitive.
 
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rayclan said:
edit: hangon i get it now.
Sweet, that's what we're here for. Welcome to the PF. :smile:
 

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