NCERT Solutions Class 7 Social Science (Geography)
The NCERT Solutions in English Language for Class 7 Social Science (Geography – Our Environment) Chapter – 5 (Water) has been provided here to help the students in solving the questions from this exercise.
Chapter – 5 (Water)
Exercises
1. Answer the following questions.
(i) What is precipitation?
Answer – Precipitation is the fall of moisture on the ground in the form of rainfall, snow, sleet and hailstones.
(ii) What is the water cycle?
Answer – The water cycle is the process by which water continually changes its form and circulates between oceans, atmosphere, and land.
(iii) What are the factors affecting the height of the waves?
Answer – Winds, earthquakes, volcanic eruption, or underwater landslides are the factors affecting the height of the waves. The stronger the wind blows, the bigger the wave becomes.
(iv) Which factors affect the movement of ocean water?
Answer – Temperature, winds, the gravitational pull of the sun, the earth, and the moon; warm and cold currents are the factors that affect the movement of ocean water.
(v) What are tides and how are they caused?
Answer – Tides are the rhythmic rise and fall of ocean water that occurs twice in a day. The strong gravitational pull exerted by the sun and the moon on the earth’s surface cause the tides.
(vi) What are ocean currents?
Answer – Ocean currents are streams of water flowing constantly on the ocean surface in definite directions.
2. Give reasons.
(i) Ocean water is salty.
Answer – Ocean water is salty because it contains a large amount of salt dissolved in it.
(ii) The quality of water is deteriorating.
Answer – The water quality is deteriorating because of human activities like –
1. Deforestation
2. Throwing garbage and other waste in water bodies
3. Chemicals released from industries
4. Increased use of fertilisers and pesticides
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
Answer – (a) Water cycle
(ii) Generally, the warm ocean currents originate near
(a) Poles
(b) Equator
(c) None of these
Answer – (b) Equator
(iii) The rhythmic rise and fall of ocean water twice in a day is called
(a) Tide
(b) Ocean current
(c) Wave
Answer – (a) Tide
4. 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 along definite paths |
| (e) Water cycle |
Answer –
| (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 along definite paths |
