Standard Science Primary 5 Systems

Siti set up a circuit with two identical bulbs and two identical batteries. She noticed the bulbs were very bright. When she added a third bulb in series, what happened to the brightness of the first two bulbs?

A Their brightness remained the same.
B They became dimmer.
C They went out completely.
D They became brighter.
Show Worked Solution

Worked Solution

Step 1: Identify the circuit type (Series). Step 2: In a series circuit, adding more bulbs increases the total resistance. Step 3: Higher resistance leads to less current flowing through the circuit. Step 4: Therefore, the bulbs become dimmer.

Correct answer: They became dimmer.

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