Equivalent Resistance/ resistors in series and parallel

In summary, the problem is asking to find the equivalent resistance, R_AB, in a network of resistors. The formulas for calculating series and parallel resistors are R_S= R1+R2+R3+...Rn and 1/RP= 1/R1 + 1/R2 + 1/R3 + 1/Rn, respectively. The equation V=IR (Ohm's law) is also relevant. The attempt at a solution involves looking at the attached file "Problem Attempt" and trying to determine the correct way to read the diagram. There is confusion about the placement of the 9 ohm resistor. It is suggested to redraw the sketch and identify which resistors should be in series and
  • #1
OmegaFury
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Homework Statement


Find R_AB in the network. Look at attached file "Problem"

Homework Equations


R_S= R1+R2+R3+...Rn (for series resistors)
1/RP= 1/R1 + 1/R2 + 1/R3 + 1/Rn... (for parallel resistors)
V=IR (ohm's law)

The Attempt at a Solution


Look at attached file "Problem Attempt"

I know I'm probably not looking at these circuits the correct way, because each time I try to solve these problems, I find different equivalent resistances depending on the order by which I use the series resistor and parallel resistor formula. I really want to know the correct way to read the diagram, because that is half the battle, and it would guide my calculations a lot more smoothly.

I'm also stuck. What do I do with that 9ohms?
 

Attachments

  • Problem.jpg
    Problem.jpg
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  • Problem attempt.jpg
    Problem attempt.jpg
    37.5 KB · Views: 498
Last edited:
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  • #2
4 ohm and 14 ohm resistors should be in series. Redraw your sketch.
 

Related to Equivalent Resistance/ resistors in series and parallel

1. What is equivalent resistance?

Equivalent resistance refers to the combined resistance of a circuit when multiple resistors are connected either in series or parallel. It is a simplified representation of the overall resistance in a circuit.

2. How do you calculate equivalent resistance for resistors in series?

To calculate the equivalent resistance for resistors in series, simply add the individual resistances together. This is due to the fact that in a series circuit, the current flowing through each resistor is the same, so the total resistance is a sum of all the resistors.

3. How do you calculate equivalent resistance for resistors in parallel?

Calculating equivalent resistance for resistors in parallel requires a different approach. In this case, the equivalent resistance is calculated by taking the reciprocal of each resistor's value, adding them together, and then taking the reciprocal of the sum. The formula for this is 1/Req = 1/R1 + 1/R2 + 1/R3 + ...

4. How does the total resistance change when resistors are connected in series vs parallel?

When resistors are connected in series, the total resistance increases. This is because the current has to flow through each resistor, and the resistance of each resistor adds up. In contrast, when resistors are connected in parallel, the total resistance decreases. This is because the current has multiple paths to flow through, and the total resistance is reduced.

5. Can the equivalent resistance ever be lower in a parallel circuit compared to a series circuit?

Yes, it is possible for the equivalent resistance to be lower in a parallel circuit compared to a series circuit. This occurs when the individual resistors in a parallel circuit have a lower resistance compared to the resistor in a series circuit. In this case, the parallel circuit provides a lower resistance path for the current to flow through, resulting in a lower equivalent resistance.

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