Standard Science Primary 5 Systems

A circuit has two bulbs, X and Y, connected in parallel. Each bulb has its own switch on its branch. If Switch X is closed and Switch Y is open, what happens?

A Only Bulb Y will light up.
B Neither bulb will light up.
C Only Bulb X will light up.
D Both bulbs will light up.
Show Worked Solution

Worked Solution

Step 1: In a parallel circuit, current can flow through multiple independent paths (branches). Step 2: Closing Switch X completes the circuit for Bulb X's branch, so it lights up. Step 3: Switch Y is open, so Bulb Y's branch is an open circuit, and it will not light up.

Correct answer: Only Bulb X will light up.

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