Which Way Does It Flow?

Why it matters

Physics has a two-hundred-year-old clerical error it never fixed: current 'flows' one way on every diagram, while the electrons actually march the other. Both camps are right — by agreement.

The idea in plain words

The two-direction treaty. Tap the terms.

conventional: + → − · electrons: − → +

A cell drives a bulb. Trace both directions.

Same circuit, same bulb, two honest arrows

• the agreement: conventional current — the official arrow, from the cell's + terminal around to − : used in every rule and diagram
• the reality: electron flow — what physically happens in metals: negative electrons drift the other way
• the pardon: why it works — negative charge one way ≡ positive the other — all formulas come out identical
• Convention: + terminal → bulb → − terminal
• Electrons: − terminal → bulb → + terminal

Predict first

In a wire, conventional current points east. The electrons drift…

Franklin guessed the moving charge was positive before electrons were found. The arrow stayed; the electrons ignore it. I points + → −; electrons go − → +.

• west — electrons are negative, they run opposite to convention — correct
• east, with the current
• nowhere — only energy moves

What you do

Set the current to 1 A, then flip to electron view and watch the same circuit march the other way.

Check yourself

In metals, the charge carriers are…

Protons are locked in nuclei; only the loose outer electrons wander — the metal's 'electron sea'.

Inside the CELL, conventional current flows…

Outside: + → −. Inside, the cell's chemical energy lifts charge back to + — completing the loop.

Fleming's rules and circuit diagrams all use…

Pick the convention and stay loyal for the whole problem — mixing directions is how signs die.

• free electrons — correct
• protons
• whole atoms
• from − to + (the chemistry pumps it uphill) — correct
• from + to −, as outside
• not at all
• conventional current — always — correct
• electron flow
• whichever you like, mixed freely