Determing the voltage drops and current through resistors

Discussion in 'Homework Help' started by AlV, Dec 30, 2006.

1. AlV Thread Starter New Member

Dec 30, 2006
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Having a prooblem solving the voltage drops and current through the following series-parallel circuit.

I have been able to get Total Resistance for the circuit and the total current, my problem is getting the current and voltage drops for the individual resistors.

Any one able to assist.

As per the request by JoeJester I've re-drawn the diagram showing how I got the total resistance and current. Where I get lost is determining the voltage drops and current through each resistor. I've tried the box diagram with each resistor and equivelant resistor but I still seem to confuse myself when doing this. Now if I understand this material correctly, R1 and R8 would have the full current going through each resistor, being in series with the power source. Where I get lost is determining the voltage through the parallel portion of the diagram. Do I first determine the current and voltage through the equivelant resistor and use that figure to determine the current through the resistors?

AlV

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2. JoeJester AAC Fanatic!

Apr 26, 2005
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AlV,

If you review http://www.allaboutcircuits.com/vol_1/chpt_5/index.html, you will see the table the author used for their series parallel analysis.

If you have constructed a table like that, post it. If you haven't, then show how you calculated the total resistance and how you calculated the total current.

3. Dave Retired Moderator

Nov 17, 2003
6,960
171
An important point with respect to series and parallel resistive circuits is:

For purely series circuits, the current through each resistor is the same.

For purely parallel circuits, the voltage across each resistor is the same.

For hybrid circuits, i.e. ones with both series and parallel arrangements, the above rules work on localised arrangements. So when looking at your circuit, try to identify where the series arrangements and parallel arrangements are and use the above rule of thumb to guide you.

The link JoeJester has provided will provide you with all the information you require to answer your questions.

Dave

4. JoeJester AAC Fanatic!

Apr 26, 2005
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AlF,

Attached is a pdf of my comments on your revised document. Some of the drawings were buried under others.

Anyways, work through the steps I've outlined.

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5. AlV Thread Starter New Member

Dec 30, 2006
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Thank you for the reply, not sure what I did with the incorrect value on R6,7. I think I now understand how to figure out the voltage drops and current through each resistor.

AlV