Building and predicting: current and charge flows

What the Activity is for

We suggest that you use parts of the circuits here to allow your class to concentrate on two aspects of the behaviour of circuits:

• Current does not get lost as it passes through circuit elements in series.
• Charge flows and currents are equivalent descriptions.

What to Prepare

• this interactive object
• software to run the interactive on a class set of computers

What Happens During this Activity

One way to use this software is to build parts of circuits and then use the current and charge flow arrows to describe them. Pupils could be involved in setting the challenges or in doing the labelling, either as a whole class activity or working in small groups. In all cases, the class can use the precision of the diagrams to fix and discuss the relative magnitudes of currents and charge flows.

For these circuits, we suggest that you use a mixture of current and charge flow labels; then increase the current and get the pupils to alter the charge flow labels to match, or change the charge flow labels and get the pupils to match the currents. An alternative is to compare lots of elements: Here are four lamps with different currents. Add charge flow representations to match these pictures.