In physics we were learning about how in series the current is the same through each resistor. So that the lightbulbs will all have the same brightness but dimmer than if there was just one bulb on there. We were explained the current being the same by Ohm's law: $V = IR$. As the resistance increases from the wire to the resistor the voltage also increases, cancelling each other out in the equation $I = \frac{V}{R}$. Leaving it as being the same.
But my question is: doesn't this only apply for Ohmic resistors, and lightbulbs aren't ohmic resistors? Would the first light bulb be brighter than the ones after it?
Best Answer
Light bulbs, or any loads, in series will all have the same current. This is unrelated to Ohm's Law - it's Kirchhoff's Current Law and it applies if the loads are ohmic or not. Assuming your source voltage stays the same, adding bulbs in series will increase the total resistance which will decrease the total current and make all the bulbs dimmer. The order of the bulbs is not significant. If one of the bulbs in series has a higher resistance it will be brighter.