Standard Science Primary 5 Systems

Look at the parallel circuit below. If Switch S1 is opened, what will happen?

A Only Bulb B2 will go out.
B Only Bulb B1 will go out.
C Both Bulb B1 and Bulb B2 will go out.
D Both Bulb B1 and Bulb B2 will remain lit.
Show Worked Solution

Worked Solution

Step 1: Locate Switch S1. It is positioned next to the battery, before the wires branch out. Step 2: This means S1 controls the main current leaving the battery. Step 3: Opening S1 breaks the main circuit, stopping current from reaching ANY branch. Both bulbs will go out.

Correct answer: Both Bulb B1 and Bulb B2 will go out.

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