Idea 3of 9Builds onThe push
The flow
What is actually moving round the loop?
Today you'll discover
- what the push sets in motion
- how the flow is counted at a point
- why it is the same everywhere in one loop
Think firstThe battery pushes. Something moves
The battery pushes. What moves through the wire?
Decide first, then press Next. Watch the arrows: the same size on every wire.
A rectangular loop of wire with a battery on the left and a bulb on the top wire, the battery's volts printed. After a prediction, arrowheads of the same size appear on every wire, then the wires before and after the bulb are marked with the same number. The last step asks how much charge passes the battery each second.
See the whole ideathe big idea and the key word, in one place
The big idea
Current is the charge flowing past a point each second.
Easy to get wrongThe battery does not supply the charge and the bulb does not burn it. The wire was full before anything was connected; the flow is that charge, moving.
Key words
- current
- the charge passing a point each second; the flow
- ampere
- the unit of current, symbol A: one coulomb passing a point each second
About this modelCharge is never used up: what leaves the battery comes back. Volts are what get spent.
Charge is never used up: what leaves the battery comes back. Volts are what get spent.
Ready to use it?
- Say which of voltage and current a described quantity is, and give the current at any point of a single loop.