Current in a Battery: Solving w/ Kirchoff's Law

In summary, the conversation discusses how to charge a dead battery by connecting it to a live battery using jumper cables. The question is asked about the current of the starter and the dead battery, with the assumption of V = 5.5 V and R = 0.50. The conversation also mentions using Kirchoff's law and provides a diagram for reference. Multiple attempts were made to find the current, but none were successful. The conversation ends with a request for help in solving the problem.
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J89
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Homework Statement


A dead battery is charged by connecting it to the live battery of another car with jumper cables. Assume that V = 5.5 V and R = 0.50 .

What is the current of the starter and the current of the dead battery?


Homework Equations


I=V/R, I1=I2+I3, basically Kirchoff's law...



The Attempt at a Solution


I thought for finding the current of the starter all, you had to do was use I=V/R, so it would 5.5/.50, but it came out wrong :(. I then tried multiplying the two resistances together..still no luck, and did V/R..still no luck, however I found that the answer comes out to be 170-171, and how I have no idea how to get that. I also tried finding the current and then subtracting it from the intial voltage and divide by the intial resistance..when I did that, I got somewhere in the 100's, but no where near the answer. I came up with millions of techniques, but none worked. Can someone help? I'm really stuck on this.

DIAGRAM BELOW FOR REFERENCE..
 

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  • #2
You've got 3 unknowns, which are [tex]I_1, I_2, I_3 [/tex]

Now search 3 equations that can solve your unknowns.
 

Related to Current in a Battery: Solving w/ Kirchoff's Law

1. What is Kirchoff's Law and how does it relate to current in a battery?

Kirchoff's Law states that the sum of currents entering and exiting a point in a circuit must be equal. This means that the current in a battery is determined by the total resistance in the circuit, as well as the voltage of the battery.

2. How do you calculate the current in a battery using Kirchoff's Law?

To calculate the current in a battery using Kirchoff's Law, you must first calculate the total resistance in the circuit by adding up all the individual resistances. Then, divide the voltage of the battery by the total resistance to get the current.

3. Can Kirchoff's Law be used for any type of battery?

Yes, Kirchoff's Law can be used for any type of battery, as long as the battery is part of a circuit with other components, such as resistors or capacitors. It is a fundamental law of circuit analysis.

4. Is Kirchoff's Law the only way to solve for current in a battery?

No, there are other methods for calculating current in a battery, such as Ohm's Law or using a multimeter to measure the current directly. However, Kirchoff's Law is a commonly used and reliable method for solving current in a battery.

5. Are there any limitations to using Kirchoff's Law for current in a battery?

Kirchoff's Law assumes that the circuit is in a steady state and that the battery has a constant voltage. If these assumptions are not met, the calculated current may not be accurate. Additionally, Kirchoff's Law does not take into account any internal resistance of the battery, which may affect the actual current in the circuit.

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