Finding equivalent resistance in complicated circuit

In summary, the conversation discusses finding a single equivalent resistor to replace multiple resistors in a circuit. The equations for series and parallel resistors are mentioned, and the person has attempted to solve the problem using different combinations. The final conclusion is that R2 and R4 are in parallel, R3 is in series with the combination of R2 and R4, and R1 is not in series with R2 and R4 due to additional connections to the circuit.
  • #1
Tekee
20
0

Homework Statement



Problem: What single, equivalent resistor could replace all of the resistors in this circuit?
Given R1 = 4, R2 = 5, R3 = 14, R4 = 9

Homework Equations



In series, R1 + R2... = Req
Parallel, 1/R1 + 1/R2... = 1/Req

The Attempt at a Solution



I have tried multiple different possibilities of series/parallel. I thought for sure that R2/R4 are in parallel, that R1 was in series with 2/4 and that R3 was in parallel with 1/2/4. When I tried this answer, I got feedback that I was wrong.
 

Attachments

  • showme.pl.gif
    showme.pl.gif
    4.2 KB · Views: 839
Physics news on Phys.org
  • #2
I would say that R2 and R4 are in parallel, call it R5
R5 is in series with R3, call it R6
R6 is in parallel with R1
 
  • #3
Your first conclusion was correct, But R1 is not in series with R2/R4.

Two resistances are in series:
- if they are connected to each other with a wire.
- if nothing else connects to this wire.

The second condition fails because the battery is also connected to the connection between
R1 and R2/R4

try to look only at what is connected to what, and not where the resistances are drawn. direction.
 

Related to Finding equivalent resistance in complicated circuit

1. How do I find the equivalent resistance in a complicated circuit?

To find the equivalent resistance in a complicated circuit, you can use Kirchhoff's laws or the equivalent resistance formula. Kirchhoff's laws state that the sum of all the currents entering a junction in a circuit is equal to the sum of all the currents leaving that junction. The equivalent resistance formula is R = V/I, where R is the equivalent resistance, V is the total voltage, and I is the total current.

2. What is the purpose of finding the equivalent resistance in a complicated circuit?

Finding the equivalent resistance in a complicated circuit allows us to simplify the circuit and make calculations easier. It also helps us understand how the circuit will behave under different conditions and allows us to design and optimize circuits for specific purposes.

3. Can I use a voltmeter and ammeter to find the equivalent resistance?

Yes, you can use a voltmeter and ammeter to find the equivalent resistance in a complicated circuit. First, measure the total voltage and total current in the circuit. Then, use the equivalent resistance formula R = V/I to calculate the equivalent resistance.

4. What should I do if the circuit has both series and parallel components?

If the circuit has both series and parallel components, you can first simplify the series components and then simplify the parallel components. After that, you can use the equivalent resistance formula to find the total equivalent resistance of the circuit. Alternatively, you can use Kirchhoff's laws to find the equivalent resistance.

5. Are there any shortcuts or tricks to finding the equivalent resistance in a complicated circuit?

There are no shortcuts or tricks to finding the equivalent resistance in a complicated circuit. The best approach is to break down the circuit into simpler components and use Kirchhoff's laws or the equivalent resistance formula to find the total equivalent resistance. However, with practice and experience, you may develop a better understanding of how to approach and solve these types of problems more efficiently.

Similar threads

Total equivalent resistance of a combined circuit
    • Introductory Physics Homework Help
Replies
7
Views
1K
Calculate the equivalent resistance
    • Introductory Physics Homework Help
Replies
11
Views
1K
The equivalent resistance for the resistors in this circuit?
    • Introductory Physics Homework Help
Replies
5
Views
1K
Voltage, Current, and Resistance Calculations
    • Introductory Physics Homework Help
Replies
13
Views
1K
Why is it important to classify circuits as series or parallel?
    • Introductory Physics Homework Help
Replies
5
Views
2K
Modification of Wheatstone Bridge
    • Introductory Physics Homework Help
Replies
5
Views
939
Equivalent Capacitance and Resistance of this Circuit
    • Introductory Physics Homework Help
Replies
27
Views
3K
Equivalent resistance of a circuit
    • Introductory Physics Homework Help
Replies
3
Views
1K
Platinum resistance thermometer and Kirchoff's Laws
    • Introductory Physics Homework Help
Replies
1
Views
2K
Determining the equivalent resistence of a circuit
    • Introductory Physics Homework Help
Replies
4
Views
1K

Hot Threads

Recent Insights

Back
Top