---
title: "Series vs parallel circuits"
description: "Describe and apply the rules for current, voltage, and resistance in series and parallel circuits, and explain the practical uses of each circuit type"
canonical: https://lightmysky.com/learn/science/series-vs-parallel-circuits-mt_loEMaQ8kFA
source: https://lightmysky.com/learn/science/series-vs-parallel-circuits-mt_loEMaQ8kFA.md
retrieved: 2026-10-19
---

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# Series vs parallel circuits

Describe and apply the rules for current, voltage, and resistance in series and parallel circuits, and explain the practical uses of each circuit type

Subject: Science · Area: Energy · Ages 12 to 13
Page: https://lightmysky.com/learn/science/series-vs-parallel-circuits-mt_loEMaQ8kFA

## Ready when they can

- States the rules for current and voltage in series circuits (current same everywhere; voltages add up)
- States the rules for current and voltage in parallel circuits (voltages same across each branch; currents add up)
- Explains why household wiring uses parallel circuits and identifies the advantage of each type

## Lesson: Series vs parallel circuits

You already know that current flows through a circuit at some voltage and meets some resistance along the way. Ohm's Law ties those three together: V = I x R, so the current through a bulb is its voltage divided by its resistance. Now look at how the parts are arranged. There are two main patterns: series and parallel.

In a series circuit, there is only one path for current to flow. That means the current is exactly the same at every point in the loop. The voltage, though, splits: each part uses some of it, and those voltage drops add up to the battery's total voltage. Break that single path anywhere and everything in the loop stops at once.

*(drawing: Two bulbs share the battery's voltage: 3V and 3V adds up to 6V total.)*

In a parallel circuit, the parts sit on separate branches. Each branch connects straight across the battery, so every branch gets the full voltage. The current is what splits this time: it divides between branches, and those branch currents add up to the total current the battery supplies.

*(drawing: Each branch runs straight across the battery, so a branch gets the whole 6V. In the series picture above, that same 6V had to split.)*

**Example.** Every lamp in your house is wired in parallel, so each one gets full voltage and works on its own path. Turn off one light and the others stay on. Old-style Christmas lights are wired in series instead, so one broken bulb breaks the only path, and the whole string goes dark.

**Recap.** Series shares one path, so current stays the same while voltage splits; parallel gives every branch full voltage while the currents add up.

## Practice

14 questions on this page, each with its working shown.

## Needs first

- [Why circuit components behave differently](https://lightmysky.com/learn/science/why-circuit-components-behave-differently-mt_-QY08-88rw)
- [Ohm's Law: voltage, current, resistance](https://lightmysky.com/learn/science/ohms-law-voltage-current-resistance-mt_H3ZDK0EYNV)
- [Circuit vocabulary](https://lightmysky.com/learn/science/circuit-vocabulary-mt_NzCNuABT3E)

## Opens up

- [Current-Voltage Graphs for Components](https://lightmysky.com/learn/science/current-voltage-graphs-for-components-mt_n_CiOa-05J)