Why Does Replacing 3.0 Ω Resistor Affect Current Through 6.0 Ω?

In summary, the conversation is discussing how the current through a 6.0 ohm resistor will be affected by a different resistor being placed in parallel with it. The expert summarizer explains that the 7.0 ohm resistor is critical in determining the current through the 6.0 ohm resistor, and any changes in the current through the 7.0 ohm resistor will also impact the current through the 6.0 ohm resistor. They also mention that any changes in the 3.0 ohm resistor will also affect the current through the 6.0 ohm resistor and other components in the circuit. The expert emphasizes the importance of understanding the relationship between voltage and current in the circuit and how any changes
  • #1
Miike012
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Question b. in paint doc.

My answer is: Becuase they said the current in question a. through the 6.0 ohm resistor is 1.0 A I am going to say the only two that will change is resistor 7.0 Ω and the newly replaced 3.0 Ω resistor... I am saying the current through the 6.0 ohm resistor will not change, but the solutions is saying it will... why? How does the different resistor (in place of the 3.0 ohm resistor) in parallel with the 6.0 ohm resistor have any effect on changing the current that banches off at the banch point?
 

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  • #2
Miike012 said:
Question b. in paint doc.

My answer is: Becuase they said the current in question a. through the 6.0 ohm resistor is 1.0 A I am going to say the only two that will change is resistor 7.0 Ω and the newly replaced 3.0 Ω resistor... I am saying the current through the 6.0 ohm resistor will not change, but the solutions is saying it will... why? How does the different resistor (in place of the 3.0 ohm resistor) in parallel with the 6.0 ohm resistor have any effect on changing the current that banches off at the banch point?

The branch consists of the 3 and 6 Ohm resistors in parallel which are in turn in series with the 7 Ohm resistor. That 7 Ohm resistor is critical. What happens if the current through the 7 Ohm resistor changes?
 
  • #3
Well if the current through the 7 ohm resistor changes from say 7 to 5 amps then the current through the 6 and 3 ohm resistors would not longer be 1.0 A + 6.0 A from each resistor respectfully, it would then be 1.0 A + 4.0A through the 6 and 3 ohm resistor. That is how I am thnking of it.
 
  • #4
Miike012 said:
Well if the current through the 7 ohm resistor changes from say 7 to 5 amps then the current through the 6 and 3 ohm resistors would not longer be 1.0 A + 6.0 A from each resistor respectfully, it would then be 1.0 A + 4.0A through the 6 and 3 ohm resistor. That is how I am thnking of it.

No. If the 3 Ohm resistor is changed, then the current through the 6 Ohm resistor will change.

If you are told that for the original configuration the current through the 6 Ohm resistor is 1.0 A, then you should be able to work out the current that flows through the 7 Ohm resistor for that configuration (as well as the current through the 3 Ohm resistor, the potential across the 3 and 6 ohm resistors, the potential across the 7 Ohm resistor, and the battery potential).

If the 3 Ohm resistor is changed to another value, then the only thing you can count on not changing is the values of the other components and the battery potential. You'll have to find the new current values and voltage drops accordingly and see what has changed.
 
  • #5
Miike012 said:
My answer is: Becuase they said the current in question a. through the 6.0 ohm resistor is 1.0 A I am going to say the only two that will change is resistor 7.0 Ω and the newly replaced 3.0 Ω resistor...
Ah! But if the current through the 7Ω changes, then (by Ohms Law) the voltage across that 7Ω will likewise change. As you can see from the circuit, the voltage across the 6Ω (and also the 3Ω) is determined as the battery voltage minus the voltage drop across the 7Ω.

So if you are correct in saying the current through the 7Ω resistor will change, then you must at the same time acknowledge that the voltage across the 6Ω will also change. And it follows that, by Ohms Law, if voltage across the 6Ω changes so must current through it.

You can't mess with logic. :smile:
 
  • #6
If 3Ω replaced means new voltage across it.
Across 6Ω voltage changes accordingly. Which means different value of current.
 
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FAQ: Why Does Replacing 3.0 Ω Resistor Affect Current Through 6.0 Ω?

1. Why does replacing a 3.0 Ω resistor affect the current through a 6.0 Ω resistor?

When a resistor is added or removed from an electrical circuit, the total resistance of the circuit changes. This change in resistance affects the flow of current through the circuit, which in turn affects the current through other components, such as the 6.0 Ω resistor.

2. How does the value of the 3.0 Ω resistor impact the current through the 6.0 Ω resistor?

The value of a resistor is directly proportional to its resistance, meaning that a higher resistance value will result in a lower current flowing through it. So, if a 3.0 Ω resistor is replaced with a higher value resistor, the current through the 6.0 Ω resistor will decrease.

3. Can replacing the 3.0 Ω resistor with a lower value resistor increase the current through the 6.0 Ω resistor?

Yes, replacing the 3.0 Ω resistor with a lower value resistor will decrease the total resistance of the circuit, allowing more current to flow through the 6.0 Ω resistor. This is because the overall resistance of the circuit is now lower, so the current has less resistance to overcome.

4. What other factors can affect the current through the 6.0 Ω resistor?

The current through a resistor is also affected by the voltage of the circuit and the resistance of other components in the circuit. If the voltage remains constant, changing the resistance of other components (such as adding or removing resistors) will also impact the current through the 6.0 Ω resistor.

5. Is there a limit to how much the current through the 6.0 Ω resistor can be affected by replacing the 3.0 Ω resistor?

Yes, the current through the 6.0 Ω resistor cannot exceed the maximum current allowed by the power supply in the circuit. Replacing the 3.0 Ω resistor with a lower value resistor may increase the current, but it cannot exceed this limit. Additionally, the current through the 6.0 Ω resistor cannot be reduced to zero, as there will always be some current flowing through the circuit due to the voltage source.

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