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Ash
Ash asked in Science & MathematicsEngineering · 4 months ago

Kirchhoffs law question?

Can somebody explain how I can do questions like this?

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2 Answers

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  • billrussell42
    Lv 7
    4 months ago
    Favorite Answer

    sum of the voltages around a loop has to be zero.

    taking CCW as +, starting at battery, and taking Vx positive as point a, we have

    +14+6–2+Vx = 0

    Vx = –14–6+2 = –18 volts

    or Vab = –18 volts

    or Vba = +18 volts

  • oldschool
    Lv 7
    4 months ago

    Assume the right side of Vx is + and the left side is -. Start at ground and sum the voltage rises and drops clockwise around the loop back to ground:

    0 - 6 -14 + Vx + 2 = 0

    +Vx  = +6 +14 -2 = 18

    Now assume the left side of Vx is +:

    0 -6 -14 - Vx +2 = 0

    -Vx = 18 or Vx = -18 because the polarity is reversed. 

    Hope this helps. 

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