Standard Science Primary 5 Systems

Jun Jie has a simple circuit with one battery and one bulb. He adds two more identical bulbs in series to the circuit. What will happen to the brightness of the first bulb?

A It will become brighter.
B It will remain the same.
C It will become dimmer.
D It will fuse immediately.
Show Worked Solution

Worked Solution

Step 1: Adding more bulbs in a series circuit increases the total resistance. Step 2: With the same battery voltage but higher resistance, the electric current flowing through the circuit decreases. Step 3: Less current passing through the filament makes the bulb dimmer.

Correct answer: It will become dimmer.

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