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Homework Help: Terminal voltage and internal resistance

  1. Feb 18, 2010 #1
    A battery labeled 12.0 V supplies 1.90 A to a 6.00 ohm resistor

    A) what is the terminal voltage of the battery?

    B) What is its internal resistance

    V = 12.0
    R = 6.00
    I = 1.90

    I think i am to use V = emf - IR for terminal voltage right? however i do not know how to get emf, and IR is current x resistance right? i got the equation off google and it didnt explain so i am assuming? i am stuck on both a and b
  2. jcsd
  3. Feb 18, 2010 #2
    12V is the emf.
    emf - IR will give you the so called "lost" volts. That is the voltage "used up" on the internal resistance.
  4. Feb 18, 2010 #3
    The 12 V is the emf. The battery is labeled with its emf.
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