Today in class, we talked about electrical circuits and examined the effect of including two lamps in one circuit.
We found that when a circuit includes two lamps in series (one right after the other), the lamps are dimmer than a single lamp in a simple circuit. This is because we have the same power source (battery) with the same voltage (1.5 V for AA) trying to convert electrical energy into another form of energy – in this case, light energy – but for two lamps instead of one — thus there is less electric potential for each lamp.
When the lamps are wired in parallel instead (next to each other), they shine with equal brightness, because in this scenario, both lamps convert the same amount of electric potential energy into light. But we noticed that the lamps in parallel do not shine as brightly as a single lamp in a simple circuit because they receive less current (moving charge).
Additionally, we saw that when we unscrewed one of the lightbulbs from the series circuit, the other light bulb when out; yet when we unscrewed one of the bulbs from the parallel circuit, the other one actually was brighter. Ask your student why this is!