1. Match the Columns:

Column A	Column B
a. The water rises to its highest level	v. High tide
b. The water falls to its lowest level	iv. Low tide
c. The highest point of a wave	i. Crest
d. The lowest point of a wave	iii. Trough
e. Moderate tides	ii. Neap tides

2. Correct the False Statements and Rewrite:

a. False: Water that contains a large amount of dissolved salts is referred to as freshwater.
Corrected: Water that contains a large amount of dissolved salts is referred to as saltwater.

b. False: Ocean currents that flow from the equator to the poles with higher surface temperatures are cold currents.
Corrected: Ocean currents that flow from the equator to the poles with higher surface temperatures are warm currents.

c. False: Due to the Coriolis Effect, the ocean currents move in an anticlockwise direction in the Northern Hemisphere and in a clockwise direction in the Southern Hemisphere.
Corrected: Due to the Coriolis Effect, the ocean currents move in a clockwise direction in the Northern Hemisphere and in an anticlockwise direction in the Southern Hemisphere.

3. Give Reasons:

a. The hydrosphere is responsible for regulating the Earth’s climate and sustaining life.

• The hydrosphere includes all water bodies like oceans, rivers, and lakes.
• It absorbs and stores heat, helping regulate Earth’s temperature.
• Oceans play a crucial role in the water cycle, ensuring the availability of freshwater.
• Marine life depends on the hydrosphere for survival, and humans rely on water for drinking, agriculture, and industry.

b. Sea water constantly moves up and down the slope of the beach.

• This movement happens due to waves and tides caused by the gravitational pull of the Moon and the Sun.
• Wind energy transfers to the surface of the ocean, creating waves that push water towards the shore.
• As the tide rises and falls, seawater moves in and out, shaping beaches and coastlines.

c. Apart from regular high and low tides, there are periods of exceptionally high or low tides.

• These extreme tides occur due to the alignment of the Sun, Moon, and Earth.
• When the Sun and Moon align, they exert a stronger gravitational force, causing spring tides (higherthannormal high tides and lowerthannormal low tides).
• When the Sun and Moon are at right angles, the gravitational pull is weaker, resulting in neap tides (moderate tides).

4. Define the Following:

a. Tidal Range:

• The difference between the height of high tide and low tide is called the tidal range.

b. Evaporation:

• The process by which water changes from liquid to gas due to heat from the Sun. It plays an important role in the water cycle.

c. Precipitation:

• When water droplets in clouds become too heavy, they fall to Earth in the form of rain, snow, sleet, or hail.

d. Transpiration:

• The process by which plants release water vapour into the air through small openings in their leaves called stomata.

e. Warm Currents:

• Ocean currents that carry warm water from the equator to the poles. They influence climate by raising temperatures in coastal areas.
• Example: Gulf Stream in the Atlantic Ocean.

5. Answer the Following Questions in Detail:

a. What causes tides? Is there any celestial body, such as a star, planet, or satellite that affects the tides?

• Tides are caused by the gravitational pull of the Moon and the Sun on Earth’s oceans.
• The Moon has a stronger influence on tides because it is closer to Earth than the Sun.
• When the Moon’s gravity pulls on Earth’s water, it creates a bulge on the side facing the Moon, causing a high tide.
• On the opposite side of the Earth, another bulge forms due to centrifugal force, creating a second high tide.
• The areas between these bulges experience low tide.
• The Sun also affects tides, but its effect is less than the Moon’s.
• When the Sun, Moon, and Earth align, spring tides occur, creating very high tides. When they form a right angle, neap tides occur, causing moderate tides.

b. What are ocean currents? What are the six factors that combine to develop them?

• Ocean currents are continuous movements of ocean water in a specific direction.
• They can be warm or cold and help distribute heat across the Earth, influencing climate.

Six Factors Affecting Ocean Currents:

1. Earth’s Rotation (Coriolis Effect):
   1. The Earth’s rotation causes currents to move clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere.
2. Wind Patterns:
   1. Winds push surface water in specific directions, forming currents.
   1. Example: Trade winds drive warm currents towards the poles.
3. Temperature Differences:
   1. Warm water is lighter and rises, while cold water is denser and sinks.
   1. This movement creates circulation patterns in the ocean.
4. Salinity Differences:
   1. Higher salt content makes water denser and causes it to sink, while less salty water rises.
   1. This process, called thermohaline circulation, helps form deep ocean currents.
5. Gravity:
   1. Ocean water moves due to differences in water levels.
   1. Gravity pulls water from higher to lower areas, creating currents.
6. Shape of Coastlines:
   1. The direction and speed of currents change when they hit continents.
   1. Example: The Gulf Stream changes direction due to the shape of North America.