Finding current in a complex circuit with resistors

In summary, the conversation discusses how to find the current through a given circuit and the confusion regarding which resistors are in series or parallel. It is concluded that no resistors are in series or parallel and the entire circuit must be solved using Kirchhoff's rules. The node-voltage method and the star-delta transformation are suggested as possible methods to simplify the circuit.
  • #1
Goomba
11
0
I am given the following circuit:
yf_Figure_26_53.jpg


How do I find the current through the battery? I have trouble seeing which resistors are in series and which resistors are in parallel. I think I need to figure that out and then calculate R_eq accordingly. Then set I=V/R and solve for I.

But which resistors are in series and which are in parallel? It's confusing the way the circuit is laid out here...
 
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  • #2
Use conservation of charge (KCL) at the two nodes across R3.
 
  • #3
Goomba said:
I am given the following circuit:
yf_Figure_26_53.jpg


How do I find the current through the battery? I have trouble seeing which resistors are in series and which resistors are in parallel. I think I need to figure that out and then calculate R_eq accordingly. Then set I=V/R and solve for I.

But which resistors are in series and which are in parallel? It's confusing the way the circuit is laid out here...

No two resistors are in series nor in parallel here. There is no way to simplify. You must solve the entire circuit using Kirchhoff's rules. Find the current flowing out of the battery (no need to find the other currents). Then just use R_eq = V_battery / I_ out of the battery.

Pat
 
  • #4
Thanks

I figured it out. :biggrin: The node-voltage method is a beautiful thing.
 
  • #5
u can also use the star-delta transformation to simplify the circuit given
 

1. How do I calculate the total resistance in a complex circuit?

To calculate the total resistance in a complex circuit, you need to first identify all the resistors in the circuit and their respective values. Then, you can use the formula R(total) = R1 + R2 + ... + Rn, where R1, R2, etc. are the individual resistances. Alternatively, you can use the parallel and series resistance formulas to simplify the circuit and find the total resistance.

2. What is the difference between series and parallel circuits?

In a series circuit, all the components are connected in a single loop, so the current flows through each component in sequence. In a parallel circuit, the components are connected in multiple branches, so the current can flow through each branch at the same time. This results in different calculations for total resistance and current in the two types of circuits.

3. How do I find the current in a complex circuit?

To find the current in a complex circuit, you can use Ohm's Law: I = V/R, where I is the current, V is the voltage, and R is the resistance. You can also use Kirchhoff's Current Law, which states that the total current entering a junction must equal the total current leaving the junction.

4. Can I use Kirchhoff's Laws in any circuit?

Yes, Kirchhoff's Laws can be applied to any circuit, whether simple or complex. These laws are fundamental principles in circuit analysis and can help you find the current and voltage in any part of a circuit.

5. How can I verify my calculations for current in a complex circuit?

One way to verify your calculations is by using a multimeter to measure the current at various points in the circuit. Another way is to use simulation software that can accurately model the behavior of the circuit and compare the results with your calculations.

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