# Calculating equivalent resistance in the following circuit

Discussion in 'Homework Help' started by natrawrs, Aug 10, 2010.

1. ### natrawrs Thread Starter New Member

Aug 10, 2010
1
0
Hi everyone,
I was given the following circuit and i have to work out the equivalent resistance in the circuit, given that each resistor has a resistance of 123456789 ohm. I havent learned much about equivalent resistance, I hope you could teach me some basics and steps on how to work it out. Thanks!

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2. ### JDT Well-Known Member

Feb 12, 2009
658
87
Start with assuming that a voltage is applied across the corners and therefore a current flows from A to B.

Note that a number of nodes in the array will have equal voltages and can be connected together without changing the operation. The circuit then becomes an array of paralleled resistors.

In fact there will be 2 paralleled resistors in series with 4 paralleled resistors in series with 6 ... (do you see where I'm going?).

Work it out assuming each resistor is 1 ohm then scale by 123456789.

Actually it's easy!

3. ### The Electrician AAC Fanatic!

Oct 9, 2007
2,621
468

This is not quite true.

It's not as easy as you think.

4. ### JDT Well-Known Member

Feb 12, 2009
658
87
Sorry, this comes of replying very quickly while I should be doing something else (working)!

But, I think I am right in saying that that points C have the same potential and can be connected together, and points D, and points E. Once you have done that resistors x and y can be replaced with a single resistor.

Then work it out with all resistors 1Ω and scale.

Yes?

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