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Voltage in Series Circuit

  1. Feb 2, 2009 #1
    1. The problem statement, all variables and given/known data
    I need to find the VOLTAGE at the end of a series of resistors, where the initial voltage is 15V

    2. Relevant equations
    R = R1+R2+R3
    I = V/R

    3. The attempt at a solution
    Total resistance = 100.05Kohm (R1+R2+R3)
    I @ Va = 15/100.05 = 14.9mA

    Now I dont know how to find the RESISTANCE at the end of the circuit (point Va)

    Any help? Im not HORRIBLE with circuits, but isnt voltage static in a series circuit? and current changes? So shouldnt the Voltage be the same at the beginning and end of the series of resistors?! :S
  2. jcsd
  3. Feb 2, 2009 #2
    Actually, in a series circuit, all components carry the same current.
  4. Feb 2, 2009 #3
    so how would i calculate the voltage at a certain point in the circuit?
  5. Feb 3, 2009 #4
  6. Feb 3, 2009 #5
    15 volts / 100.05 ohms = .1499 amperes (which is 149.9 mA)

    Since you know the current (correct current is .1499 amperes) flowing through ALL the series resistors, merely measuring the voltage drop across the resistor in question, then divide that voltage drop by your current of .1499 amperes and it will yield the resistance value of that resistor in ohms.
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