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Resistors in Series Calculator

Total resistance of components in a chain.

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Total Resistance

Formula first

Overview

In a series circuit, resistors are connected end-to-end along a single path, forcing the same electrical current to flow through each component sequentially. The total or equivalent resistance of the network is calculated by summing the individual resistance values of every component in the chain.

Symbols

Variables

R_T = Total Resistance, R_1 = Resistor 1, R_2 = Resistor 2, R_3 = Resistor 3

Total Resistance
Resistor 1
Resistor 2
Resistor 3

Apply it well

When To Use

When to use: Apply this formula when components are arranged in a single loop without any branching paths. It assumes that the current remains constant through all components and that the wiring resistance between resistors is negligible.

Why it matters: This principle is fundamental for designing voltage dividers and controlling current levels in electronic devices. It allows engineers to create specific resistance values for a circuit by combining standard, commercially available resistor components.

Avoid these traps

Common Mistakes

  • Using the parallel formula.
  • Forgetting to add all resistors.

One free problem

Practice Problem

A simple circuit is constructed by connecting three resistors in a single loop with values of 12 Ω, 33 Ω, and 45 Ω. What is the total equivalent resistance of the circuit?

Resistor 112 Ω
Resistor 233 Ω
Resistor 345 Ω

Solve for:

Hint: The total resistance is found by summing the three individual resistances directly.

The full worked solution stays in the interactive walkthrough.

References

Sources

  1. Halliday, Resnick, and Walker, Fundamentals of Physics
  2. Wikipedia: Series and parallel circuits
  3. Halliday, Resnick, Walker, Fundamentals of Physics, 11th ed.
  4. Wikipedia: Electrical resistance
  5. Halliday, Resnick, Walker, Fundamentals of Physics, 10th ed.
  6. Bird, Stewart, Lightfoot, Transport Phenomena, 2nd ed.
  7. IUPAC Gold Book, 'Ohm's law'
  8. IUPAC Gold Book, 'Ohmic conductor'