What fixes how big or small the electric current is?
Teaching Guidance
for 11-14
The battery gives
a current
Wrong Track: The current flowing in the circuit is 2 ampere. The battery is giving a current of 2 ampere.
Right Lines: The current in the circuit is 2 ampere. This rate of flow of charge is fixed by choosing the battery and the lamp, so the voltage and the resistance.
The circuit as a system
Thinking about the learning
Having been introduced to the idea of measuring electric currents, some pupils see the battery as providing a fixed current. This incorrect line of thinking may be linked to the earlier wrong track
idea that the current originates in the battery.
Thinking about the teaching
You should always talk so that the pupils see the circuit as a whole system with the charge being set in motion by the battery and any resistance in the circuit acting to impede that motion. So do try to avoid any discussion of the
current moving from place of place, or splitting.
