Standard Science Primary 6 Energy

Siti set up a circuit with two identical bulbs and two identical batteries in series. She then added a third identical bulb in series to the same circuit. What would happen to the brightness of the bulbs?

A All bulbs will become dimmer.
B The brightness will remain the same.
C All bulbs will become brighter.
D The first two bulbs will stay the same, but the third will be dim.
Show Worked Solution

Worked Solution

Step 1: Identify that the bulbs are in series. Step 2: In a series circuit, adding more bulbs increases the resistance to the flow of electricity. Step 3: Higher resistance means less current flows through each bulb. Step 4: Therefore, the bulbs become dimmer.

Correct answer: All bulbs will become dimmer.

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