Question

What will happen to the brightness of a string of bulbs hooked up in series when you increase the number of bulbs in the string?

Answer 1

Each light in the string will get dimmer. Let us look at what is causing this. The scenario provided is that of a Series circuit. In the case of a series circuit, the current flowing through each of the load (String of bulbs in our example) is same, while the voltage drops equally across all the bulbs (provided all the bulbs are of the same rating) For example if we have a 230 V AC supply, and we have connected 10 bulbs in series, the voltage across each of the bulbs is (230/10=23 V). As you can see, if you add more bulbs, the voltage at each bulb drops further, causing them to dim. Hence, each light in the string will get dimmer as you add more lights. Option (B) is the answer.