Question

Two identical light bulbs are connected to a battery. Will the light bulbs be brighter if they are connected in series or in parallel?

Short answer

Answer: The light bulbs will be brighter when connected in parallel.

Step-by-step solution

Recall the difference between series and parallel configurations

In a series connection, all components are connected end to end, so that there is only one path for the current to flow. In a parallel connection, the components are connected in multiple paths such that the current is divided among the paths.

Understand the effect of the connections on the voltage and current

In a series connection, the voltage across each component is different and the current through each component is the same. In a parallel connection, the voltage across each component is the same and the current through each component is different.

Determine the brightness of the bulbs in a series connection

The voltage from the battery is divided equally across both light bulbs in a series connection. Since the bulbs are identical, they will each get half of the total voltage from the battery. The brightness of a light bulb depends on the power it consumes (P=IV), and since the voltage across each bulb is lower in a series connection, their brightness will be less.

Determine the brightness of the bulbs in a parallel connection

In a parallel connection, the voltage across each bulb is the same as the voltage of the battery. The current through each bulb is also the same, as they are identical. The power consumed by each bulb will therefore be higher, making them brighter when connected in parallel.

Conclusion

The light bulbs will be brighter when connected in parallel compared to a series connection, as they receive the full voltage from the battery and consume more power in a parallel configuration.