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Difficult : Calculate equivalent resistance of the circuit problem .

  • Thread starter agoogler
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  • #1
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Homework Statement



Calculate the total equivalent resistance between A and D -
r8ibJ.png

( All resistors are 1 ohm )

Homework Equations


-


The Attempt at a Solution


The only thing I can see is that the two straight 1 ohm resistors are in parallel , giving 1*1/1+1= 1/2 resistance. But what next , please help !
 

Answers and Replies

  • #2
berkeman
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Homework Statement



Calculate the total equivalent resistance between A and D -
r8ibJ.png

( All resistors are 1 ohm )

Homework Equations


-


The Attempt at a Solution


The only thing I can see is that the two straight 1 ohm resistors are in parallel , giving 1*1/1+1= 1/2 resistance. But what next , please help !
It's not clear what you mean by "the two straight 1 ohm resistors", but try this...

Since B and C are open circuits for this question, delete their respective 1 Ohm resistors. Then re-draw the circuit, with A at the top and D at the bottom. See if you can draw the resistors in a more normal configuration, using this simplification...
 
  • #3
CWatters
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The only thing I can see is that the two straight 1 ohm resistors are in parallel , giving 1*1/1+1= 1/2 resistance.
There are no resistors directly in parallel so the above can't be right.

Do what berkeman said.
 
  • #4
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It's not clear what you mean by "the two straight 1 ohm resistors", but try this...

Since B and C are open circuits for this question, delete their respective 1 Ohm resistors. Then re-draw the circuit, with A at the top and D at the bottom. See if you can draw the resistors in a more normal configuration, using this simplification...
Okay.
After deleting those two , I can see two pairs of resistors in series giving 2 each. Then these two 2 ohm resistors are in parallel , giving 1 ohm. Now these is in series with the remaining two 1 ohm resistors giving 3 ohm as the answer. Am I correct ?
 
  • #5
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I am sure that you are correct.
 
  • #6
CWatters
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I agree.
 
  • #7
According to Wheatstone bridge
Answer is 7/4 ohms that is 1.75 ohms
Am I correct ?
 
  • #8
gneill
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20,802
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According to Wheatstone bridge
Answer is 7/4 ohms that is 1.75 ohms
Am I correct ?
No. Show your work. Or better yet, start a new thread since this is a rather old thread (from 2013) and the Original Poster hasn't been logged in since 2015.
 

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