Equivalent resistance across a circuit made of 12 resistors

In summary, the conversation discusses how to solve a circuit and determine the equivalent resistance between two points. The main point of contention is whether the circuit is symmetrical or not. If it is symmetrical, the potential at certain points will be equal and the current can be simplified using series and parallel resistors. If the circuit is not balanced, Kirchhoff's Laws can be used to determine the equivalent resistance.
  • #1
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hey can anybody please tell me how to solve this circuit?? :confused:

I tried this sum out but I can't understand which points are symmetrical and have same potential..or how the current is distributed
 

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  • #2
The symmetry means that potential at C=D=E=F = 0.5 the pd between A and H
This means there is no current through the arms CD and FG. So you can ignore the 2 resistors there.
This allows you to simplify the circuit using series and parallel resistors.
 
  • #3
ok, I solved the combinations and I got 3/4 R.
but what if the circuit is not symmetrical..that is if we have to find the equivalent resistance between A and B?
 
  • #4
I also get 3/4 R.
If the circuit is not balanced, I can't see much use for it! Usually, these "bridge" type circuits are only useful when balanced. [eg Wheatstone bridge]

To attempt to answer the question, though, one possibility would be to set up a system of Kirchhoff's Law equations for the various closed loops (where ΣIR = 0) as well as the main circuit supplying the pd that provides the main current.
You would get 6 equations with 6 unknowns and a relationship between the main current and the applied pd. This would give the equivalent R.
 
  • #5


I would suggest approaching this circuit problem by using the principles of Ohm's Law and Kirchhoff's Laws. These laws state that in a series circuit, the total resistance is equal to the sum of individual resistances, and in a parallel circuit, the total resistance is less than the smallest individual resistance.

To solve this circuit, you can start by identifying which resistors are in series and which are in parallel. In a series circuit, the current remains constant throughout, so the current passing through each resistor will be the same. In a parallel circuit, the current is divided among the branches, so the total current will be equal to the sum of the currents in each branch.

After identifying the series and parallel sections of the circuit, you can use the equations for equivalent resistance in series and parallel to calculate the total resistance of the circuit. Once you have the total resistance, you can then use Ohm's Law (V=IR) to calculate the current passing through each resistor.

As for identifying symmetrical points and potential, this would require a deeper understanding of the circuit and its components. You may need to use Kirchhoff's Laws, which state that the sum of all currents entering a junction is equal to the sum of all currents leaving the junction, and the sum of all potential differences in a closed loop is equal to zero.

In summary, to solve this circuit, you will need to apply the principles of Ohm's Law and Kirchhoff's Laws, as well as identify the series and parallel sections of the circuit. It may also be helpful to draw a schematic diagram to better visualize the circuit and its components.
 

1. What is equivalent resistance?

Equivalent resistance is a single resistance value that represents the total resistance of a circuit. It is calculated by combining all individual resistances in a circuit using Ohm's law.

2. How is equivalent resistance calculated in a circuit with 12 resistors?

In a circuit with 12 resistors, the equivalent resistance can be calculated by adding all 12 resistances together. For resistors connected in series, the equivalent resistance is the sum of all individual resistances. For resistors connected in parallel, the equivalent resistance is calculated using the formula 1/Req = 1/R1 + 1/R2 + ... + 1/Rn, where Req is the equivalent resistance and R1, R2, and so on are the individual resistances.

3. Does the arrangement of resistors affect the equivalent resistance?

Yes, the arrangement of resistors does affect the equivalent resistance. In a series circuit, the equivalent resistance is equal to the sum of all individual resistances, while in a parallel circuit, the equivalent resistance is less than the smallest individual resistance.

4. Why is equivalent resistance important?

Equivalent resistance is important because it helps us understand how the total resistance in a circuit affects the flow of current. It is also useful in calculating the power dissipated by the circuit and determining the voltage drop across each resistor.

5. Can the equivalent resistance of a circuit with 12 resistors ever be zero?

No, the equivalent resistance of a circuit with 12 resistors can never be zero. In a series circuit, the equivalent resistance is always greater than zero, while in a parallel circuit, it can only be zero if all individual resistances are zero, which is not possible in a circuit with 12 resistors.

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