class 7- Water

These are caused due to gravitational pull of the sun and the moon.

• Waves

• Tides

• Ocean currents

These are caused due to earthquakes or volcanic eruptions.

• waves

• currents

• tsunami waves

The rise and fall of water in a wave represent ____ and ____ respectively.

• trough, crest

• wavelength, crest

• crest, trough

During _______tide, the high tides are the highest and low tides are the lowest.

• spring tide

• Neap tide

• Low tide

These currents flow from the equatorial region towards the polar regions.

• Cold currents

• Warm currents

• Both

The total amount of freshwater present on earth is_____.

• 97%

• 3%

• 21%

The movement of ocean water in the form of a stream, in a definite direction, on the ocean surface is called__________.

• Tides

• Ocean currents

• waves

The average temperature near the equator is about _____.

• 10°C

• 20°C

• 26°C

The ______ in Asia has highest salinity.

• Red Sea

• Dead Sea

• Mediterranean Sea

The average salinity of ocean water is________ per thousand.

• 26

• 35

• 1000