Finding the Current Through a Resistor (Working With Parallel and Series)

In summary: A are both correct.In summary, the conversation discussed finding the equivalence resistance and current in a circuit with series and parallel resistors. The solution involved solving for voltage in series resistors and current in parallel resistors. The final answer was found to be 0.17A, with some discrepancy due to the given significant figures. The conversation also referenced a helpful video on Khan Academy.
  • #1
Oannes
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Homework Statement
What is the Current Through A Resistor in Parallel?
Relevant Equations
I = V/R
Resistors in Parallel => 1/R = 1/R1 + 1/R2
Resistors in Series => R = R1 + R2
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Here is the actual question.

And here is my attempt at a solution
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In Summary I did the following
  1. Found the Equivalence Resistance to Be 5.9 ohms and the Current throughout the entire resistor to be 1.53 Amperes
  2. Worked backwards from my resistor simplifications. When the resistors were in series I solved for V because they should have the same Current. When they were in parallel I solved for Current because they had the same voltage.
  3. Eventually I worked my way back to the parallel resistors of 4.3 and 12 ohms and got .166 Amperes of current running through the 12 ohms resistor.
  4. This answer, however, was wrong. I found this method from this video on Khan Academy https://www.khanacademy.org/science...-example-finding-current-voltage-in-a-circuit.
 

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  • #2
Your work looks correct to me. I carried an extra significant figure through the calculation and got an answer of 0.1679 A. But some of the resistors and the battery voltage are given with only 1 significant figure! So, I think two significant figures in the answer should suffice: 0.17 A.
 
  • #3
TSny said:
Your work looks correct to me. I carried an extra significant figure through the calculation and got an answer of 0.1679 A. But some of the resistors and the battery voltage are given with only 1 significant figure! So, I think two significant figures in the answer should suffice: 0.17 A.

You are exactly right thanks a bunch. I was going mad trying to figure out where i was going wrong.
 
  • #4
Yes, 0.168A
 

FAQ: Finding the Current Through a Resistor (Working With Parallel and Series)

What is a resistor?

A resistor is an electrical component that is designed to resist the flow of electrical current. It is typically made of a material with high resistance, such as carbon or metal, and is used to control the amount of current in a circuit.

What is the difference between series and parallel circuits?

In a series circuit, the components are connected in a single path, so the current flows through each component in succession. In a parallel circuit, the components are connected in multiple paths, so the current is divided among the components.

How do you calculate the total resistance of a series circuit?

To calculate the total resistance of a series circuit, you simply add up the individual resistances of each component. This is because the current flows through each component in succession, so the total resistance is equal to the sum of the individual resistances.

How do you calculate the total resistance of a parallel circuit?

To calculate the total resistance of a parallel circuit, you use the formula 1/Rt = 1/R1 + 1/R2 + 1/R3 + ..., where Rt is the total resistance and R1, R2, R3, etc. are the individual resistances. This formula takes into account the fact that the current is divided among the components in a parallel circuit.

How do you find the current through a resistor in a circuit?

To find the current through a resistor in a circuit, you can use Ohm's law, which states that current (I) is equal to voltage (V) divided by resistance (R). This means that I = V/R. Alternatively, you can use the formula V=IR, where V is voltage, I is current, and R is resistance.

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