Electricity & Magnetism / circuits / current
Current Is Not Used Up
The misconception
That current leaves the battery, gets partly eaten by the first bulb, and arrives diminished at the second — so the bulb nearer the battery should be brighter. Wrong about current, and it blocks every later circuit idea until it is replaced.
The same current flows into and out of every element in a series circuit; what a bulb converts is energy, delivered by charge that keeps moving. Ammeters on both sides of the bulb read the same, and everything about brightness follows from power, not from current being consumed.
Nothing published references it yet, so it sits low in the queue.