[Urgent] Homework help (DC Circuits)

Discussion in 'Homework Help' started by pmendz2010, Mar 24, 2011.

  1. pmendz2010

    Thread Starter New Member

    Mar 24, 2011
    8
    0
    Hello guys! I have a homework in DC Circuits and I need to submit it tomorrow but I don't think I do not have much time if I do it alone since I still got a lot of homeworks to do for my major subjects. So if anyone can help me, I am willing to pay someone who can give me a step-by-step solution for this problem. I really need to get this done. Here's the problem:


    Solve the voltages between each of the nodes (Va, Vb, Vc, and Vd) and ground in the figure shown.

    (image attached)





    Anyone? Please?
     
    • EE.png
      EE.png
      File size:
      12.6 KB
      Views:
      43
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
  3. pmendz2010

    Thread Starter New Member

    Mar 24, 2011
    8
    0
    Uhmm.. Sorry but I don't think you are getting the point right.
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Our policy on homework starts with -
    We must insist that you show work.
     
  5. pmendz2010

    Thread Starter New Member

    Mar 24, 2011
    8
    0
    Yep! I am fully aware of that and I did try solving the problems and I finished all of it except this one. I'm kinda new to DC Circuits and I am quite stuck in this one problem. Unfortunately, I think I am running out of time so I asked for help in this forum. :(

    I am sorry if I am causing you trouble. :( Thanks for the help though.
     
  6. pmendz2010

    Thread Starter New Member

    Mar 24, 2011
    8
    0
    After combining R1 & R3, and R2 & R4, what am I supposed to do with the wire below R7 and R8?
     
  7. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Kinda looks like a 0 ohm resistor in parallel.
     
  8. pmendz2010

    Thread Starter New Member

    Mar 24, 2011
    8
    0
    I see. So the voltage there is also 0. Is it safe if I just neglect that wire and continue solving as if that wire isn't there?
     
  9. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    As if those two resistors aren't present.
     
  10. pmendz2010

    Thread Starter New Member

    Mar 24, 2011
    8
    0
    Are you referring to R7 and R8? But how would I solve for the voltages between the nodes and the ground if those two resistors are neglected?
     
  11. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    They are shorted by the wire. They have no effect.
     
  12. Georacer

    Moderator

    Nov 25, 2009
    5,142
    1,266
    beenthere are you sure the resistors R7 and R8 are to be neglected? The way I see it, the order of the simplifications is:

    Ra=R1//R3
    Rb=R2//R4
    Rc=R5//Ra
    Rd=R6//Rb
    Re=Rc//Rd
    Rf=R7//R8
    Rtot=Rf+Re

    Can you have another look?
     
  13. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Yes, I did not see the lack of a connector dot between R7, R8 and ground.
     
  14. pmendz2010

    Thread Starter New Member

    Mar 24, 2011
    8
    0
    Sorry but what does that mean?
     
  15. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    It means that I walked into a trick school problem.

    The resistor net is redrawn per the attachment. There is an interesting connection missing.

    Note to self: never assume a school problem is supposed to represent anything in the real world.
     
  16. pmendz2010

    Thread Starter New Member

    Mar 24, 2011
    8
    0
    Sorry for the bother but I'm a bit confused with simple things and I need clarification.

    Consider the image attached, what would be the value of V1 (voltage across R1)?
     
  17. Georacer

    Moderator

    Nov 25, 2009
    5,142
    1,266
    Can any voltage be produced on the same node of a circuit?
    The two ends of the resistor are essentially the same point in the circuit, and voltage is defined as the difference of potential energy between two points of the circuit.
     
Loading...