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Simple electrical circuits: cells, bulbs, switches, conductors and insulators An electrical circuit is a complete loop that electricity can flow around. A simple circuit has a cell (battery), wires and a component such as a bulb or buzzer. If there is a gap anywhere, nothing works.
Ages 7–14 (rough guide)
Level Foundation
Subject Science
Time 15–20 minutes
Format Online + printable
Stage UK Years 4 and 6 · roughly US Grades 4–5 1 Learn it2 See it worked3 Try it online4 Print it5 Check your answerBefore you start
Who it's for and what to know first Knows some everyday things that use electricity. Safety: only experiment with small batteries, never mains sockets.
The cell pushes electricity around the circuit. Several cells joined together make a battery. The loop must be complete, with no gaps, for current to flow. A switch opens (breaks) or closes (completes) the circuit. Conductors let electricity through — most metals such as copper and steel. Insulators do not — plastic, rubber, wood, glass. In a series circuit, adding more cells makes a bulb brighter; adding more bulbs with the same cells makes each one dimmer. Voltage, measured in volts (V), describes how hard the cell pushes. Worked example 1
A bulb will not light. The wires are connected to both ends of the cell and the bulb. What could be wrong? Check the switch is closed. Check for a loose connection that leaves a gap. Check the cell is not flat and the bulb is not broken. Answer: Open switch, loose connection, flat cell or broken bulb.
Try it online · print it · check it
Practice questions Foundation · ages 7–14
Simple electrical circuits Name Date
Write one word or a short answer.
1. Will a bulb light if there is a gap in the circuit? (yes/no) 2. What provides the push in a simple circuit? 3. Is copper a conductor or an insulator? 4. Is plastic a conductor or an insulator? 5. Which component opens and closes a circuit? 6. Add a second cell in series. Does the bulb get brighter or dimmer? 7. Add a second bulb in series with one cell. Brighter or dimmer? 8. What is the unit of voltage? Write one word or a short answer.
1. Will a bulb light if there is a gap in the circuit? (yes/no) no 2. What provides the push in a simple circuit? cell 3. Is copper a conductor or an insulator? conductor 4. Is plastic a conductor or an insulator? insulator 5. Which component opens and closes a circuit? switch 6. Add a second cell in series. Does the bulb get brighter or dimmer? brighter 7. Add a second bulb in series with one cell. Brighter or dimmer? dimmer 8. What is the unit of voltage? volt Connecting both wires to the same end of the cell. Thinking all metals-looking things conduct — painted or plastic-coated items may not. Testing with mains electricity. Never do this. Last reviewed: 25 September 2026
