Trace the connections, test a loop and explain when a component can work.
What it is about
Identify complete simple circuits with cell, wires, lamp, buzzer or motor.
Year 4 · 8–9 years · 30 challenges
Before you begin
Lower KS2 enquiry, skeletons, light, materials and fair comparisons.
What the class will do
Sort into groups · 8 challenges
Trace complete routes
Use each record’s actual contacts and working-part conditions. A route must pass through the component between both cell ends.
Predict and experiment · 5 challenges
Test a model loop
Predict together and manipulate the fixed cell, bulb and two-switch series model. Only the observed lit/dark outcome is assessed.
Choose and explain · 17 challenges
Explain the connections
Use the supplied evidence to compare parts, complete routes, outputs and safe classroom boundaries.
Using it in class
Everyone traces or predicts before a rotating representative acts. Records describe working, compatible classroom parts; the screen model has one ideal cell, bulb and two switches. No mains experiments. Full bank 35–45 minutes, longer with extended discussion; choose short rounds or one block.
Give everyone time to think and discuss before one pupil acts at the board. The class explains and confirms together; hints and explanations stay until you move on.
Use an up-to-date browser on a computer connected to a whiteboard or shared display. Touch, mouse and keyboard; optional audio and reduced motion. No pupil accounts or personal devices.
Choose from 5 challenges up to the full activity. Discussion determines the duration: you set the pace.
A look inside the activities
Sort into groups
Working classroom lamp and cell; conducting wires. Sort these connection records by whether they make a complete loop THROUGH the lamp.
One cell end → lamp → other cell end; no gaps
Both lamp connections go to the same cell end
One cell end → lamp; no connection back
Groups: Complete loop through lamp · No complete loop through lamp
Explanation and discussion
A complete conducting loop uses both cell ends and passes through the lamp. A missing return or two connections to the same cell end does not provide that working circuit.
Why is having two wires not enough information by itself?
Predict and experiment
Make this model bulb light by completing its conducting loop. Predict the needed switch states before you record the result.
The model at the start
Switches 1 and 2 are open. In the game, open or close them and observe the bulb.
Experiment: electric circuit. The class predicts, changes one condition and compares what happens.
Explanation and discussion
Both switches closed complete the route through the ideal cell and bulb. One remaining gap anywhere in this single loop keeps the bulb dark.
Can the class trace the complete route through the bulb and back to the cell?
Choose and explain
A working lamp has one connection to a cell, but no route back to its other end. Will this simple circuit light the lamp?
Yes; one cell connection is always enough
Yes; being close to the other cell end completes the route
No; there is no complete conducting loop
Explanation and discussion
The lamp needs a complete conducting loop between the two cell ends, through its contacts. Nearness and a single wire do not provide that return route.
What connection is missing from the supplied record?
Find the fault safely
Switches control flow
Conductors and insulators