---
title: "Will the bulb light up?"
description: "Identify whether or not a lamp will light in a simple series circuit, based on whether the lamp is part of a complete loop with a battery"
canonical: https://lightmysky.com/learn/science/will-the-bulb-light-up-mt_NNNbPccwB4
source: https://lightmysky.com/learn/science/will-the-bulb-light-up-mt_NNNbPccwB4.md
retrieved: 2026-10-19
---

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# Will the bulb light up?

Identify whether or not a lamp will light in a simple series circuit, based on whether the lamp is part of a complete loop with a battery

Subject: Science · Area: Energy · Ages 8 to 9
Page: https://lightmysky.com/learn/science/will-the-bulb-light-up-mt_NNNbPccwB4

## Ready when they can

- Predict whether a lamp will light by tracing the circuit for a complete loop
- Explain that a gap anywhere in the circuit breaks the loop and the bulb won't light
- Identify the fault in a non-working circuit (e.g. loose wire, missing connection)

## Lesson: Will the bulb light up?

Ben's torch went dark, so trace the circuit like a path before swapping parts. Start at the cell, follow each wire, and check that the path connects all the way back to the cell. If the path is complete, the bulb lights. If there's a break anywhere, it won't. A wire that only looks joined but does not touch still counts as a break.

*(drawing: The loop in order: cell, wire, bulb, wire, and back to the cell. Every step connects, so this bulb lights.)*

*(drawing: The loop in order with a gap: cell, wire, gap, wire, bulb, wire, and back to the cell. The bulb will not light.)*

**Example.** Zara looks at her circuit: a cell, two wires, and a bulb. She traces the loop with her finger, cell to wire to bulb to wire and back to the cell. Every connection touches the next one, so she knows the bulb will light before she even flips it on.

**Tip.** A gap doesn't have to be a missing wire. Sometimes a wire looks connected but isn't quite touching. Check every single connection, not just most of them, since one gap anywhere stops the whole loop.

**Recap.** To predict whether a bulb lights, trace the whole loop from the cell and back. If there is one gap anywhere, it stays off.

## Practice

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

## Needs first

- [Building a simple circuit](https://lightmysky.com/learn/science/building-a-simple-circuit-mt_DA7-JYRvtP)

## Opens up

- [How switches work](https://lightmysky.com/learn/science/how-switches-work-mt_Hah24nbToi)