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1. About _____% of the earth surface is covered by water.
2. The up and down movements seen on the surface of ocean water are known as ____ .
(b) Ocean Currents
3. The _____ of the winds blowing over the ocean is the most important cause of the waves.
(a) Pulling action
(b) Pushing action
4. Tides are caused mainly by _____.
(a) attraction of the moon
(b) gravitation of the earth
(c) friction of winds
5. Select from the following a warm current of the Atlantic Ocean.
(a) Gulf stream
(b) Kuroshio Current
(c) Labrador current
6. Which of the following is the source of fresh water?
(c) Snow and ice
7. The raised part of the wave is called the _____ of the wave and lower part is called the ____ of the wave.
(a) trough and crest
(b) crest and trough
(c) crest and tough
8.North Western Europe is warmer than north- eastern America due to_______.
(a) lower latitude
(b) ocean current
(c) lower altitude
9. The cyclones produce very high waves in the sea, so __________ coast of India experiences such high waves during the summer months.
10.The periodic rising and falling of sea waters.
(C) Ocean Currents
11._____ occur when the sun, the moon and the earth are in a straight line.
(a) Spring tides
(b) Neap Tides
(c) Bore Tides
12. ______ occur when the sun, the moon and the earth form three corners of a triangle, the attraction of the sun and Moon neutralize each other.
(a) Bore Tides
(b) Spring tides
(c) Neap Tides
13.____ currents are those that originate near the equator and flow towards the poles.
14. Ocean Currents are formed by the difference in the density of sea water. This difference is because of variation in _____ and salinity.
15.The mixing of warm and cold currents helps in the production of __
(c) red algae