NCERT Solutions for Class 7 Geography Chapter 5 – Water

NCERT Solutions for Class 7 Geography Chapter 5 – Water

1. Answer the following questions.

(i) What is precipitation?

Answer –

When the water vapour reaches the dew point and condenses, precipitation occurs within the cloud and falls under the force of gravity. The main forms of precipitation include : –

• Drizzle,
• Rain,
• Sleet,
• Snow,
• Graupel ; and
• Hail.

(ii) What is water cycle?

Answer – Water cycle,  is a continuous phenomenon . It describes the following : –

• How water evaporates from the surface of the earth from the rivers, sea, lakes, rises into the atmosphere,
• How water cools and condenses into rain or snow in clouds, and
• How water falls again to the surface as precipitation.

(iii) What are the factors affecting the height of the waves?

Answer – There are many factors affecting the height of waves.  Some of factors affecting the height of waves are as under : –

a. Slope of the land
b. Wind velocity
c. Underwater earthquake
d. Volcanic activity in the sea
e. Underwater land slides.

NCERT Solutions for Class 7 Geography Chapter 5 – Water

(iv) Which factors affect the movement of ocean water?

Answer – The ocean water moves from one place to the other horizontally as well as  vertically.  The factors affecting movement of ocean water  are as under :

a. Difference in temperature
b. Difference in density
c. Difference in salinity
d. Tidal forces of sun and moon

(v) What are tides and how are they caused?

Answer – Tides are the rhythmic rise and fall of the ocean water that occurs approximately twice in a day. When the water level becomes high it is known as high tide, when the water level is comparatively low it is known as a low tide.

The tides are caused by the gravitational attraction of the sun and moon which exerts force on the water bodies and causes a bulge of water on that area causing high tides.

(vi) What are ocean currents?

Answer – Ocean currents are streams of horizontal and vertical movements of the water masses that is produced by gravity, wind friction, and water density variation in different parts of the ocean. The ocean currents may be warm or cold

NCERT Solutions for Class 7 Geography Chapter 5 – Water

2. Give reasons.

(i) Ocean water is salty. The main source of water in the oceans are rivers which carry sediments, minerals, soil and other particles from the mountains and plain lands. When these rivers discharge themselves in the sea, they also pour the minerals and rocks which contain several salts giving the ocean water a salty taste.

(ii) The quality of water is deteriorating. With the rise in population, there is a demand for food which leads to more industries. These industries dump their wastes in the rivers, lakes, oceans which deteriorates the quality of water. Some other causes of the quality of water deterioration are: acid rain, oil spill in the oceans.

NCERT Solutions for Class 7 Geography Chapter 5 – Water

3. Tick the correct answer.

(i) The process by which water continually changes its form and circulates between oceans, atmosphere and land
(a) Water cycle
(b) Tides
(c) Ocean currents

(ii) Generally the warm ocean currents originate near
(a) Poles
(b) Equator
(c) None of these

(iii) The rythmic rise and fall of ocean water twice in a day is called
(a) Tide
(b) Ocean current
(c) Wave

4. Match the following.

NCERT Solutions for Geography (Social Science)

• Chapter 1 – Environment
• Chapter 2 – Inside Our Earth
• Chapter 3 – Our Changing Earth
• Chapter 4 – Air
• Chapter 5 – Water
• Chapter 6 – Natural Vegetation and Wild Life
• Chapter 7 – Human Environment: Settlement Transport and Communication
• Chapter 8 – Human Environment Interactions
• Chapter 9 – Life in the Deserts