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Heat — Science STD 7 — Question

Gujarat BoardEnglish MediumSTD 7ScienceHeat1 Mark
MCQ
Ventilators are provided at the top of a room:
  • A
    To bring oxygen for breathing.
  • B
    So that sunlight may enter the room.
  • ✓
    To maintain convectional currents to keep the air fresh in the room.
  • D
    To provide an outlet for carbon dioxide.
✓

Answer

Correct option: C.
To maintain convectional currents to keep the air fresh in the room.
Hotter air has lower density in compare to cold air. The air we exhale is relatively hotter than the air present in the room so that hotter air moves upwards and normal air in the room seat downward. this process happens continuously, and at the top level in the room, hot air gets collected. To exhaust that air from the room we provide ventilators at the top. Ventilators also help to inter fresh air inside the room. The process of flow of air is known as conventional current.

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