A Journey through States of Water MCQs for UPSC Prelims

Tiny drops appear on the outside of a glass holding cold lemon water. Where do these drops come from?

1. A From the lemon water, which leaks out through the glass
2. B From water vapour present in the air around the glass
3. C The glass itself makes water when it is cold
4. D They are small pieces of ice thrown out by the drink

Consider these statements. I. Melting and freezing are opposite changes. II. Evaporation changes a liquid into a gas. Which is correct?

1. A Only II
2. B Only I
3. C Neither I nor II
4. D Both I and II

A boy walks in from a cold veranda into a warm kitchen and his spectacles at once turn foggy. Where does the water on the lenses come from?

1. A From the cold outdoor air, which sticks to the lenses as he walks
2. B From vapour in the warm kitchen air, which condenses on the cold lenses
3. C From his eyes, which water in the warm room
4. D From water stored inside the glass of the lenses

Assertion (A): Wet clothes hung in the shade of a veranda still become dry. Reason (R): Water can evaporate only in direct sunlight.

1. A Both A and R are true, and R is the correct explanation of A
2. B Both A and R are true, but R is not the correct explanation of A
3. C A is true, but R is false
4. D A is false, but R is true

The forming of water drops on a cold surface is called

1. A boiling
2. B melting
3. C evaporation
4. D condensation

Ramesh has to dry a wet mop indoors on a damp day. Which step will help most?

1. A Open it out fully and keep a fan blowing on it
2. B Fold it and keep it inside a closed bucket
3. C Leave it bunched up in a still corner of the room
4. D Wrap it in a plastic sheet so that it stays clean