CBSE Class 7 - Geography - NCERT Chapter 5 Solutions - Water

Water

NCERT Chapter 5 Solutions

Q1: What is precipitation?

Answer: The condensation of water vapour in the form of water droplets or ice crystals and their falling on the earth surface is known as precipitation.


Q2: What is water cycle?

Answer: Endless movement of  water from sea to air, air to land and from land back to sea is called water or hydro-logical cycle.


➽ Watch online flash animation on Water Cycle.


Q3: What are the factors affecting the height of the waves?

Answer:  Winds and Weather conditions


Q4: Which factors affect the movement of ocean water?

Answer:

• waves
• tides
• currents
• earthquakes
• underwater volcanic eruption
• underwater landslide

Q5: What are tides and how are they caused?



Answer: The regular rise and fall in sea is called tide. Tides are caused by mainly the attractive forces of the moon and to some extent by the sun. The moon as compared to the sun is near to the earth. The moon exerts more influence causing tides on the earth.


Q6: What are ocean currents?


Answer:  Winds blows across the surface of the sea or ocean create current. When sea water moves continuously in a particular direction a current is formed. These are of two types:

• cold and 
• hot currents.

Ocean currents affect the coastal region.


Q7: Give reasons.
(i) Ocean water is salty.
(ii) The quality of water is deteriorating.

Answer:

(i) Ocean water contains large amount of dissolved salts.
(ii) Due to pollution, addition of chemical wastes are main causes for deteriorating quality of water.


Q8(MCQ): The process by which water continually changes its form and circulates between oceans, atmosphere and land

(a) Water cycle
(b) Tides
(c) Ocean currents

Answer: (a) Water cyle


Q9(MCQ): Generally the warm ocean currents originate near

(a) Poles
(b) Equator
(c) None of these

Answer: (b) Equator


Q10(MCQ): The rhythmic rise and fall of ocean water twice in a day is called

(a) Tide
(b) Ocean current
(c) Wave


Answer: (c) Tide

Q11: Match the following.

(i)   Caspian Sea (a) Largest lake
(ii)  Tide (b) Periodic rise and fall of water
(iii) Tsunami (c) Strong seismic waves.
(iv)  Ocean currents (d) Streams of water moving in definite paths.


Answer: (i) - a, (ii) - b, (iii) - c, (iv) - d