Current & Voltage Course

Lesson 11 of 16: Series vs Parallel Comparison

Move step by step through the course and keep track of where you are.

Simulation

Series vs Parallel Comparison

Compare the same two resistors in two different circuit layouts to see how current, resistance, and voltage behavior changes.

Voltage

12.0 V

Series I

1.00 A

Parallel I

4.50 A

Comparison

Parallel draws more current

Core idea

Series adds resistance and keeps one current path. Parallel lowers equivalent resistance and lets current divide into branches.

Simple idea

Same parts do not always behave the same way. The circuit layout changes the result.

Series circuit

One path, same current everywhere.

+121212.0VR1 = 4.0 OhmR2 = 8.0 OhmDrop = 4.0VDrop = 8.0VI = 1.00 AFlow: 40%Level: Low

Parallel circuit

Same voltage across both branches, current splits.

+121212.0VR1 = 4.0 OhmR2 = 8.0 OhmI1 = 3.00 AI2 = 1.50 AItotal = 4.50 AFlow: 100%Level: High
Comparison View

Watch the behavior change with layout

This simulation compares the same source and the same two resistors in both layouts, so you can see how series and parallel rules produce different results.

Series total resistance

12.0 Ohm

In series, resistor values add directly because the current follows one path.

Parallel equivalent resistance

2.67 Ohm

Parallel branches lower the overall resistance seen by the source.

Key result

Parallel draws more current

With the same voltage and resistor values, parallel usually allows more total current.

What to notice

Series and parallel can use the same parts, but their path structure changes the rules. Series keeps one current path. Parallel keeps the same voltage across multiple branches.

Beginner Summary

Keep the comparison picture in mind

This lesson becomes easier when you keep one picture in mind: series is one path, and parallel is many paths. That one difference changes how the whole circuit behaves.

Same parts can behave very differently when the layout changes.

Series

Series circuits have one path. Resistances add together, and the same current flows through every part.

Parallel

Parallel circuits have multiple paths. Each branch gets the same voltage, while current splits between the branches.

Key comparison

With the same resistors, parallel usually draws more total current because the equivalent resistance is lower than in series.