Ohm's Law Quiz 2 of 5

Discussion in 'General Electronics Chat' started by T.Jackson, Nov 23, 2011.

  1. T.Jackson

    Thread Starter New Member

    Nov 22, 2011
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    Code ( (Unknown Language)):
    1.  
    2.  
    3. [FONT=Fixedsys]                         o <---- 1.35V ----> o                          
    4.                          |                   |                  
    5.                          |                   |                  
    6.                          |                   |                  
    7.   5v o--/\/\/--+--/\/\/--+--/\/\/--+--/\/\/--+--/\/\/--+--/\/\/--o GND
    8.           R1        R2        R3        R4        R5        R6[/FONT]
    9.  
    10.  
    Calculate R1 to R6. Choose your own IT or RT.
     
  2. DerStrom8

    Well-Known Member

    Feb 20, 2011
    2,428
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    This is looking suspiciously like you're having us do your homework...... :p
     
    Last edited: Nov 24, 2011
  3. T.Jackson

    Thread Starter New Member

    Nov 22, 2011
    328
    14
    No sir. Please answer the question.
     
  4. T.Jackson

    Thread Starter New Member

    Nov 22, 2011
    328
    14
    Soon I think we create a special forum with an entry exam.

    We don't want ya if you don't know what you're talking about.
     
  5. Georacer

    Moderator

    Nov 25, 2009
    5,142
    1,266
    Please watch your language when you are addressing your fellow members.

    These threads don't seem to constitute any project. They will be move to the General Electronics Chat forum.
     
  6. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    Who crowned you hall monitor?
     
  7. bountyhunter

    Well-Known Member

    Sep 7, 2009
    2,498
    507
    DEFINE IT and RT
     
  8. Jony130

    AAC Fanatic!

    Feb 17, 2009
    3,957
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    R3 = R4 = 10K;

    R3+R4 = 20K

    IT = 1.35V/20k = 67.5uA

    R1 + R2 + R5 + R6 = (5V - 1.35V)/67.5uA = 54.074K

    R1 = R2 = 10K

    R5 = 1K and R6 = 33K
     
  9. Wendy

    Moderator

    Mar 24, 2008
    20,766
    2,536
    If you go to my blog you can find a set of templates for drawing electronics I call Paint CAD. Your drawing could be redrawn thusly...

    [​IMG]

    Without more information the problem is insoluble, or to phase it differently, there are an infinite number of solutions. Total current (It) is critical, but then you need to know the relationship between R1 and R2, R3 and R4, and R5 and R6.

    I suspect the OP is trying to get a feel for the skill levels here. We have a spread of members from PHDs to complete beginners (some of the latter are children) who all are interested in electronics. All of the guys who have responded so far can do this in their sleep.

    We have a couple of new projects in the Completed Projects area, check them out.
     
    Last edited: Nov 24, 2011
  10. SgtWookie

    Expert

    Jul 17, 2007
    22,182
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    Well, looks like T.Jackson composed the ASCII divider in WordPad or the like instead of Notepad. Proportional fonts just don't work well with ASCII graphics.

    Here's how it's supposed to look:
    Code ( (Unknown Language)):
    1.                          o <---- 1.35V ----> o                          
    2.                          |                   |                  
    3.                          |                   |                  
    4.                          |                   |                  
    5.   5v o--/\/\/--+--/\/\/--+--/\/\/--+--/\/\/--+--/\/\/--+--/\/\/--o GND
    6.           R1        R2        R3        R4        R5        R6
     
  11. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    One way to do it:
    Code ( (Unknown Language)):
    1. It = 0.1 Amperes (declared)
    2. Junction between R4 and R5 is now declared as node N1
    3. Junction between R2 and R3 is now declared as node N2
    4. Vt = 5 Volts          (known; given in problem statement)
    5. Rt = Vt/It            (50 Ohms)
    6. VN2N1 = 1.35          (V(N2)-V(N1), known; given as 1.35V in problem statement, given a name for calculation purposes.)
    7. R3R4pct = VN2N1/Vt    (27%; calculate percent of total)
    8. RR3R4 = Rt * R3R4pct  (R3+R4 = 13.5 total resistance)
    9. R6 = RANDOM(Rt-RR3R4)         (R6 is a random number between 0 and 36.5 inclusive)
    10. R5 = RANDOM(Rt-(RR3R4+R6))    (R5 is a random number between 0 and the sum of R6, R4, and R3)
    11. R2 = RANDOM(Rt-(RR3R4+R5+R6)) (R2 is a random number between 0 and the sum of R6, R5, R4, and R3)
    12. R1 = Rt - (R2+RR3R4+R5+R6)    (R1 is the remaining resistance, if any)
    13. R4 = RANDOM(RR3R4)            (R4 is a random number between 0 and RR3R4)
    14. R3 = RR3R4 - R4               (R3 is whatever's left of RR3R4 after R4)
     
    Last edited: Nov 24, 2011
  12. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,435
    1,305
    Is this one of those psych homework assignments where they ask people annoying questions and then log how people respond and how annoyed they get as the situation escalates?
     
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