The currents are flowing in the direction indicated by the arrows. A negative current denotes flow opposite to the direction of the arrow. Asume the batteries have zero internal resistance. Find (part 1)the current through the 5.3 ohm resistor and the 3.1 V battery at the top of the circuit and (part 2) the current through the 23.1 ohm resistor in the center of the circuit.
Here is the circuit in question: http://img260.imageshack.us/img260/6863/physicseg7.th.png [Broken]
V = IR
The Attempt at a Solution
I solved the problem but to be honest I plugged in numbers until I got the right answer. I do not understand the concept (but I would like to!) behind the problem and would really like some help decoding the problem. Here was my thought process...
Part 1 - the overall voltage in the circuit is the sum of 3.1 V and 18.6 V. The current is flowing through from the positive termial of the 18.6 V battery, splits at the junction, and flows across the 5.3 ohm resistor. Since the battery has no internal resistance, current will be reduced across the 5.3 ohm resistor but would not be affected as it goes through the battery. Similarly, the current moves from the second battery, across the 23.1 ohm resistor and across the 5.3 ohm resistor. So, I = (18.6 V + 3.1 V)/5.3 ohm = 4.09 A
Part 2 - The current flows from the 18.6 V battery, across the 23.1 ohm resistor. I = 18.6 V/23.1ohm = -.805 A
I'm probably completely wrong here...but I'd really like to learn the concept behind the problem. If anyone could please explain to me where my thought process is flawed, and help me derive/understand what's going on in the diagram, I would greatly appreciate it. Thanks!
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