Multiple choice

Why dew drops are formed on the outer surface of a glass of chilled water?

  1. Molecules of water pass through the minute pores of the glass and deposit on its surface due to the low temperature.

  2. Cold water droplets spill over the surface of the glass at the time of filling.

  3. Glass reacts with chilled water and expels water molecules out of it.

  4. The vapour in air condenses on the cool surface of the glass resulting in fine dew drops.

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

When moist air comes in contact with the cooler surface, the vapourised form of water condenses. Thus dew drops are formed. 

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