# Complex resistor problem

• mitsuruangel
In summary, the conversation discusses a circuit with 5 resistors connected to a battery with a known emf. The question is to find the current in resistor R1 and the current through all other resistors. The student mentions using the loop rule to solve for each unknown but is having trouble with the math. They also mention trying to solve using the KCL node equations.

## Homework Statement

Five resistors with resistance R1 = 4.90 Ω, R2 = 7.30 Ω, R3 = 8.80 Ω, R4 = 2.70 Ω, R5 = 5.00 Ω, are connected to a battery with emf E = 8 V in the circuit shown. What is the current in resistor R1?
I also need the current through all other resistors. I know you need to use the loop rule and solve for each unknown but I can't seem to get any of them. I don't know if I'm doing my math wrong or what but it is getting very frustrating.
The red arrows are the current arrows I am trying to work with

## Homework Equations

1)I1=I5+I2=0
2)I4=I3+I5=0
3)V-I1R1-I2R2=0
4)V-I3R3-I4R4=0
5)V-I1R1-I5R5-I4R4=0
6)V-I3R3+I5R5-I2R2=0
7)I3R3-I1R1-I5R5=0
8)I5R5-I2R2+I3R3=0

## The Attempt at a Solution

I have tried solving for each but I get lost in the rearranging
Any help would be awsome...or maybe some easier way to go about it?

Last edited:
mitsuruangel said:

## Homework Statement

Five resistors with resistance R1 = 4.90 Ω, R2 = 7.30 Ω, R3 = 8.80 Ω, R4 = 2.70 Ω, R5 = 5.00 Ω, are connected to a battery with emf E = 8 V in the circuit shown. What is the current in resistor R1?
I also need the current through all other resistors. I know you need to use the loop rule and solve for each unknown but I can't seem to get any of them. I don't know if I'm doing my math wrong or what but it is getting very frustrating.

Welcome to the PF. You need to show us your work before we can help you. Show us the loop equations that you have been working with and having problems. We cannot help you (per the PF Rules link at the top of the page) unless you show us some work.

Also, I generally prefer to use the KCL node equations instead of the KVL loop equations. Maybe try it both ways to see if you like one way better.

We were not shown the KCL node equations

## 1. What is a complex resistor problem?

A complex resistor problem is a type of electrical engineering problem that involves analyzing a circuit with multiple resistors connected in series or parallel. The goal is to determine the equivalent resistance of the circuit and calculate the current or voltage at different points in the circuit.

## 2. How do I solve a complex resistor problem?

To solve a complex resistor problem, you need to use Ohm's law and Kirchhoff's laws to analyze the circuit. Start by simplifying the circuit into its equivalent resistance, then use Ohm's law to calculate the current or voltage at different points. Finally, use Kirchhoff's laws to analyze the current flow and voltage drops in the circuit.

## 3. What are the common types of complex resistor problems?

The most common types of complex resistor problems are series and parallel circuits. In a series circuit, the resistors are connected end to end, while in a parallel circuit, the resistors are connected side by side. There are also more complex circuits with a combination of series and parallel connections.

## 4. How do I handle non-ideal resistors in a complex resistor problem?

Non-ideal resistors, such as temperature-dependent or non-linear resistors, can make solving a complex resistor problem more challenging. In these cases, you may need to use more advanced techniques, such as Thevenin's theorem or nodal analysis, to analyze the circuit. It is important to carefully read and understand the problem to determine the best approach.

## 5. What are some tips for solving complex resistor problems?

Here are a few tips that can help you solve complex resistor problems more efficiently:

• Start by drawing a clear and accurate circuit diagram.
• Identify series and parallel components to simplify the circuit.
• Label the current and voltage at different points in the circuit.
• Apply Ohm's law and Kirchhoff's laws methodically.
• Double-check your calculations and use units consistently.