Q1. Answer the following questions briefly.
A). What is precipitation?
Ans. Falling of moisture in the form of rainfall, snow, fog, sleet and hailstone is termed as precipitation.
B). What is water cycle?
Ans. The water cycle is the process by which water continuously changes its form and circulates between oceans, atmosphere and land.
C). What are the factors affecting the height of the waves?
Ans. Waves, earthquakes, volcanic eruption and under water disturbances are the factors affecting the height of the waves.
D). Which factors affect the movement of ocean water?
Ans. Temperature, winds, gravitational pull of the sun and the moon.
E). What are tides and how are they caused?
Ans. Tides are the rhythmic rise and fall of ocean water that occur twice a day. The strong gravitational pull exerted by the sun and the moon on the earth’s surface causes the tides.
F). What are ocean currents?
Ans. Ocean currents are streams of water flowing constantly on the ocean surface in definite directions.
Q2. Give reasons.
A). Ocean water is salty.
Ans. The water of oceans is salty as it contains a large amount of dissolved salt.
B). The quality of water is deteriorating.
Ans. Water is being used injudiciously. Industrial effluents and untreated water of industries and sewer water also gets mixed into streams and rivers. So the quality of water is deteriorating day by day.
Q3. Tick the correct answer.
A). The process by which water continually changes its form and circulates between oceans, atmosphere and land.
I). Water cycle
Ii). Tides
Iii). Ocean currents
B). Generally the warm ocean currents originate near-
I). Poles
Ii). Equator
Iii). None of these
C). The rhythmic rise and fall of ocean water twice in a day is called-
I). Tide
Ii). Ocean current
Iii). Wave
Q4. Match the following.
Ans.
Caspian sea – largest lake
Tide – periodic rise and fall of water
Tsunami – strong seismic waves
Ocean currents – streams of water moving along definite paths.