everyday science MCQ #2247

After long periods of use, a grey spot develops on the inside of a bulb. This is because:

everyday science MCQ #2247

  1. Question 1

    Q1. After long periods of use, a grey spot develops on the inside of a bulb. This is because:

    • A) The tungsten filament evaporates and collects there
    • B) The heat of the bulb scorches the glass at the top
    • C) Dust inside the bulb condenses on the top
    • D) Glass undergoes a change due to the heat

    Answer: The tungsten filament evaporates and collects there

    Explanation: Tungsten filaments in incandescent bulbs slowly evaporate at high temperatures and the metal vapor deposits as a grey film on the cooler glass at the top of the bulb.