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 first lamp shines more brightly the second. Because we know that electric circuits are a way to convert electrical energy into another form of energy – in this case, light energy – we learned that the second lamp is dimmer because the first lamp converts some of the electric potential energy into light energy. The second lamp therefore has less potential energy to convert into light. If you unscrew the light bulb of any of the bulbs in series, the rest will all go out. Ask students why this happens.
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. Also, if you unscrew the bulb of a light bulb in parallel the other bulbs will still work. Ask your student why this is!