The parallel connection

The two lights shine as brightly as if they were connected individually to the battery in a separate circuit. Both lights shine brighter than they would in a series connection if the same battery were used. If one lamp is removed, the other will continue to shine with the same brightness.

Wrap a connecting wire around each of the terminals of a flat battery. The ends of the connecting wires are now attached to the first bulb holder. Then connect the second bulb holder to the first bulb holder using the two connecting wires. Now screw both bulbs into the socket.

• 1 flat battery (4.5V),
• 4 connecting wires,
• 2 bulbs (3.5 V / 0.2 A),
• 2 sockets,
• possibly 1 screwdriver,

If, contrary to expectations, an attempt does not succeed, the following points should be investigated first:

1. Are all wires at the contact points completely free of insulation? (It must be the bare wire).
2. Is the battery still intact? It is conceivable that the batteries will run out in the course of the lesson! (Hold an incandescent lamp to the pole plates: the lamp must shine brightly and constantly!)
3. Is the light bulb working? (The filament must not be defective!)

What is behind the experiment

Each light bulb has its own separate circuit. The current paths run in parallel and do not influence each other. Both bulbs are connected to a branched circuit, which means that both bulbs receive the same amount of current independently of each other. The same voltage also acts on both lamps, which is why one lamp can be removed and the other has the same voltage as before. In the parallel circuit, each bulb is therefore in its own circuit and the current paths run in parallel. Therefore, one of the two bulbs can be turned out without the other going out.

What the experiment has to do with everyday life

If, for example, you turn out one of the bulbs in a ceiling light with several light bulbs, the others will still light up, so it is a parallel circuit.

Anja Kopschitz