Which way does current go?
Round the circuit, from positive to negative.
A direction to follow
A lamp glows. Electric current is flowing round the circuit. But current has a direction. It has to go somewhere.
Which terminal of the cell do you think the current leaves from?
What this lesson covers
The idea
The direction of electric current in a closed electrical circuit is taken to be from the positive to the negative terminal of the electric cell.
A direction to follow
A lamp glows. Electric current is flowing round the circuit. But current has a direction. It has to go somewhere.
Which terminal of the cell do you think the current leaves from?
- The positive (+) terminal
- The negative (–) terminal
- Both at the same time
Follow the arrows
The circuit is joined and the lamp glows. Tap the cell terminal you think the current leaves from. Then turn the cell round and do it again.
Plus to minus
The direction of electric current in a closed electrical circuit is taken to be from the positive to the negative terminal of the electric cell.
When you turn the cell round, the positive terminal changes places, and so do the arrows. The rule stays the same.
- The current... | Goes
- leaves the cell from | the positive (+) terminal
- passes through | the wires and the lamp
- comes back to the cell at | the negative (–) terminal
Notes
Current is taken to flow from the cell's positive (+) terminal, through the circuit, to its negative (–) terminal.
Check yourself
In a closed circuit, the current is taken to go from the _ terminal of the cell to its _ terminal.
The cell is turned round, so its metal cap (positive) is now at the bottom. Where does the current leave the cell?
A student says "the current leaves from the negative terminal". Is this right?
The current goes round the loop and reaches the cell again at its...
- negative, positive. It is the other way round.
- positive, negative — correct. Yes! Positive to negative.
- positive, positive. A cell has one positive terminal. The current goes to the other one.
- At the top, because it is on top. Top or bottom does not matter. The current leaves from the positive terminal.
- At the bottom, from the cap — correct. Yes! It leaves from the positive terminal, wherever it is.
- It stops flowing. The circuit is still complete, so the current still flows.
- Yes. No: the direction is taken to be from positive to negative.
- No, it is taken to leave from the positive terminal — correct. Yes! Leaves from +, returns to –.
- It depends on the lamp. The direction rule is about the cell, not the lamp.
- negative terminal — correct. Yes! It returns to the negative terminal.
- positive terminal. It leaves from the positive one.
- metal body. The body is not a terminal.