Class 6 NCERT Solutions Science Chapter 14 - Water

145

146

Water Exercise 145

Solution 1

(a)   Evaporation
(b)   Condensation
(c)   Drought
(d)   Floods

Concept insight: Recall water cycle in nature.

Solution 2

(a)   Condensation
(b)   Evaporation
(c)   Condensation
(d)   Evaporation
(e)   Evaporation

Concept insight: Recall the terms used in water cycle.

Solution 3

Only (c) and (e) are true.

Concept insight: Important from Exam Point of View.

Water Exercise 146

Solution 4

Yes, if we spread our school uniform near an anghithi or heater it will dry quickly as it will provide heat to water and it will convert into vapours quickly thus it will dry up quickly.

Concept insight: Recall the process of evaporation.

Solution 5

A puddle of water is formed around a cool bottle because the water vapours near the cold bottle collide with it and lose their heat and condense.

Concept insight: Recall the process of condensation.

Solution 6

During exhalation, carbon dioxide is released along with water vapours. If one breathes out, the released water vapours collide with the surface of the glass, thereby making it cooler. As a result, the water vapours present in the air surrounding the glass condense and get attached to the glass surface. Consequently, the glass becomes wet.

Concept insight: Recall the process of condensation.

Solution 7

As air moves up in the atmosphere, it cools down at a sufficient height. The air becomes so cool that water vapour present in it condense to form small water droplets which remain suspended in the atmosphere. These suspended water droplets appear as clouds.

Concept insight: Recall the formation of clouds

Solution 8

Drought occurs when an area does not receive rainfall for a period of year or more. Due to this, soil continues to lose water by evaporation and transpiration and becomes dry.

Concept insight: What happens if it does not rain for a long period?