need some help!!!!!

Discussion in 'General Electronics Chat' started by bwormee32, Oct 19, 2008.

  1. bwormee32

    Thread Starter New Member

    Oct 19, 2008
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    i am a first year electroincs student.. i am haveing a bit of trouble with series/parellel circuits...the problem thet i am haveing is finding out witch resistors are in series and witch ones are in parellel..is their a easy way to figure this out??? i think i am just looking to much into the problems, makeing them much harder than they really are.. thank you very much for all the help......
     
  2. mik3

    Senior Member

    Feb 4, 2008
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    If two or more resistors have their one side terminals connected together and their other side terminals also connected together then they are in parallel.

    Resistors in series have just one common terminal
     
  3. bwormee32

    Thread Starter New Member

    Oct 19, 2008
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    i think i understand this with just resistors, but when you put it in a problem is where i get lost...
     
  4. mik3

    Senior Member

    Feb 4, 2008
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    Post an example to guide you
     
  5. Farlander

    Active Member

    Oct 14, 2008
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    Imagine it like, if the electricity only has one way to go, it is wired in series. In parallel, the current can choose multiple paths.
     
  6. bwormee32

    Thread Starter New Member

    Oct 19, 2008
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    how do i get a pic to post ???
     
  7. mik3

    Senior Member

    Feb 4, 2008
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    You can photograph the display of your PC with the print screen button on the keyboard. You can find a circuit on the internet and post its link too.
     
  8. SgtWookie

    Expert

    Jul 17, 2007
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    Below the "Quick Reply" box, there is a "Go Advanced" button. Click it.
    On the next screen that comes up, below the reply box in the "Additional Options" area, there is a "Manage Attachments" button. Click that.

    A new window will pop up (make sure you allow popups for this site).
    Click a "Browse" button on the right. Navigate to where your photo is stored (.PNG files preferred) and click on it. Click OK.
    After you are done selecting up to three files to attach, click the "Upload" button.

    Then close the window. Note that the size of the files you can upload are limited.
     
  9. bwormee32

    Thread Starter New Member

    Oct 19, 2008
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    these are just a few of the problems i have to work on.. i just need some way to understand how to figure it out... i know the formulas,i just need a to get it in my head...thanks

    [​IMG] [​IMG] [​IMG] [​IMG] [​IMG]
     
  10. mik3

    Senior Member

    Feb 4, 2008
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    Ok lets take figure 6.20

    R7, R8 and R9 are in series so we add them to get say Ra=R7+R8+R9

    Then Ra is in parallel with R5, we make the calculation to get Rb=Ra//R5

    Then R4, Rb and R6 are in series, we calculate to get Rc=R4+Rb+R6

    Then Rc is in parallel with R2, calculate them to get Rd=Rc//R2

    Finally, R1, Rd and R3 are in series, calculate to get Requivalent=R1+Rd+R3

    Ra, Rb, Rc and Rd are just the values of some of the combinations, dont get confused. Also, this // means in parallel.
     
  11. SgtWookie

    Expert

    Jul 17, 2007
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    Fig. 6-8:
    R2 and R3 are in series. R2+R3=Ra.
    Then Ra and R4 are in parallel.
    Rb=(Ra x R4) / (Ra + R4)

    Then R1, Rb, and R5 are in series. Add them up.
     
  12. bwormee32

    Thread Starter New Member

    Oct 19, 2008
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    thank you very much..i am going to try to solve some of these and see if i can get this stuck into my thick head..thanks again
     
  13. SgtWookie

    Expert

    Jul 17, 2007
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    Try a few - then take a break :) Letting your subconcious chew on things for a bit can help sort things out.

    A couple of quick cross-checks:
    When you're calculating the total resistance of two or more resistors in parallel, your result will always be less than the smallest resistor's value.
    When you're calculating the total resistance of two or more resistors in series, your result will always be greater than the largest resistor's value.
     
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