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Homework Help: Help test tomorrow. this may be on it.

  1. Apr 9, 2008 #1
    Ok, I already got all 6 points off on this homework problem:( but it might be on the test tomorrow. I know what the answers should be. He says you apply Kirchoff's rule, I've tried, and I don't get the right answers. Help! if you can get (a) I can get the rest.

    Two batteries and a 50-ohm resistor are connected in a single, simple loop. The first battery has an EMF of 15 V and an internal resistance of 9 ohms. The second battery has an EMF of 9 V and an internal resistance of 4 ohms. The circuit is connected in such a way that first battery is trying to drive current clockwise in the circuit while the second battery is trying to drive current counterclockwise.

    For questions (a) through (f) below, enter each answer as a positive number.

    (a) How much current flows in the circuit?

    0.0952 (real answer)
  2. jcsd
  3. Apr 9, 2008 #2
    Draw a picture and use Ohm's law. The sum of the voltages around the loop will equal 0.
  4. Apr 9, 2008 #3

    Let's say I don't know what that is... I drew a picture. Ohm's law is v=ir but what do I do about the internal resistance, or that one's pushing current one way, and one's pushing current the other way...
  5. Apr 9, 2008 #4
    That's the sweet thing about V=IR. Internal resitance, and the Source Voltage tells you how much Current the source is developing, does it not?
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