Question

linh builds a circuit from the diagram shown. if linh removes bulb 3, which bulbs will remain lit? 1 only 1 and 2 only 4 only 1, 2, and 4

Explanation:

In a parallel - series circuit, bulbs 1 and 3 are in parallel. Bulbs 2, 4 and the parallel combination of 1 and 3 are in series. When bulb 3 is removed, the parallel branch with bulb 1 is still a closed path (since removing one component in a parallel branch doesn't break the other parallel path). So current can still flow through bulb 1, then through bulb 2 and bulb 4 (as they are in series with the parallel branch of 1 and 3, and removing 3 doesn't break the path for 1, 2, 4).

Answer:

1, 2, and 4