Class 7 Geography Chapter 5 Water Extra Questions and Answers
Class 7 Geography Chapter 5 Water extra questions and answers available here. Solving class 7 extra questions help students to revise the Chapter most competently. We prepared these questions as per the latest NCERT book and CBSE syllabus. Practicing these extra questions before the exam will ensure excellent marks in the exam.
Water Class 7 Geography Extra Questions and Answers
Very Short Extra Questions and Answers
1: An artificial enclosure for keeping small house plants is called ____________
Answer: Terrarium
2: The major source of fresh water is the rivers, ponds, springs, and glaciers. (T/F)
Answer: True
3: Two third of the earth surface is covered by water. (T/F)
Answer: False
4: ____________ is celebrated as world water day.
Answer: 22nd march
5: The rhythmic rise and fall of ocean water twice in a day is called ____________
Answer: Tide
6: During neap tide sun, moon and earth lies in straight line.(T/F)
Answer: False
7: High tide helps in navigation. (T/F)
Answer: True
8: The areas where warm and cold current meet provide the best fishing grounds of the world. (T/F)
Answer: True
9: ____________ is the southernmost point of India.
Answer: Indira point
10: The process by which water continuously changes its form and circulates between ocean, atmosphere and land is called ____________
Answer: Water cycle
11: Seismic activity is more prone in Pacific Ocean (T/F)
Answer: True
12. Which is the largest lake in the world?
Answer: Caspian Sea
Short Extra Questions and Answers
1. What is a terrarium?
Answer: It is an artificial enclosure for keeping small house plants.
2. What is meant by the term salinity?
Answer: Salinity is the amount of salt in grams present in 1000 grams of water.
3. What is the salinity of Dead Sea?
Answer: Dead Sea in Israel has salinity of 340 grams per litre of water.
4. How is it possible to float in the Dead Sea?
Answer: Swimmers can float in it because the increased salt content makes it dense.
5. Why is the ocean salty?
Answer: The water of the oceans is salty or saline as it contains large amount of dissolved salts.
6. What is the effect of high tide?
Answer: It is high tide when water covers much of the shore by rising to its highest level.
7. What is the effect of low tide?
Answer: It is low tide when water falls to its lowest level and recedes from the shore.
8. What are the major sources of freshwater?
Answer: The major sources of fresh water are the rivers, ponds, springs and glaciers.
9. When is world water day celebrated?
Answer: March 22 is celebrated as World Water Day when the need to conserve water is reinforced in different ways.
10. What is the first indication of a tsunami?
Answer: The first indication that tsunami is approaching is the rapid withdrawal of water from the coastal region, followed by destructive wave.
11. Why is water essential for our survival?
Answer: Water is absolutely essential for survival. Water alone can quench our thirst when we are thirsty.
12. What happened to the Indira point during the tsunami of 2004?
Answer: The Indira point in the Andaman and Nicobar islands got submerged after the tsunami.
13. Name one warm ocean current and one cold ocean current?
Answer: The Labrador Ocean current is cold current while the Gulf Stream is a warm current.
14. What is Tsunami?
Answer: Tsunami is a series of huge tidal waves caused by earthquakes or other disturbance under the sea.
15. What are ocean currents?
Answer: Ocean currents are streams of water flowing constantly on the ocean surface in definite directions.
16. Where does the word tsunami come from and what does it mean?
Answer: Tsunami is a Japanese word that means “Harbour waves” as the harbours get destroyed whenever there is tsunami.
17. What is precipitation?
Answer: Precipitation is any type of water that forms in the Earth’s atmosphere and then drops onto the surface of the Earth.
18. What is water cycle?
Answer: The process by which water continually changes its form and circulates between oceans, atmosphere and land is known as the water cycle.
19. What are tides and how are they caused?
Answer: The rhythmic rise and fall of ocean water twice in a day is called a tide. The strong gravitational pull exerted by the sun and the moon on the earth’s surface causes the tides.
20. Which factors affect the movement of ocean water?
Answer: Temperature, density and salinity, storm, earthquake, a volcanic eruption or underwater landslides, gravitational pull exerted by the sun and the moon on the earth’s surface.
21. Why is our earth like a terrarium?
Answer: Our earth is like a terrarium. The same water that existed centuries ago still exists today. The water used to irrigate a field in Haryana may have flowed down the Amazon River a hundred years ago.
Long Extra Questions and Answers
1. Write a short note on waves?
Answer: When the water on the surface of the ocean rises and falls alternately, they are called waves. During a storm, the winds blowing at very high speed form huge waves. These may cause tremendous destruction.
2. What are the factors affecting the height of the waves?
Answer: During a storm, the winds blowing at very high speed form huge waves. An earthquake, a volcanic eruption or underwater landslides can shift large amounts of ocean water. As a result a huge tidal wave called tsunami, that may be as high as 15m., is formed.
3. What are spring and neap tides?
Answer: The water of the earth closer to the moon gets pulled under the influence of the moon’s gravitational force and causes high tide. During the full moon and new moon days, the sun, the moon and the earth are in the same line and the tides are highest. These tides are called spring tides. But when the moon is in its first and last quarter, the ocean waters get drawn in diagonally opposite directions by the gravitational pull of sun and earth resulting in low tides. These tides are called neap tides.
4. Why are tides important to us?
Answer: Tides important to us because:
- High tides help in navigation.
- They raise the water level close to the shores. This helps the ships to arrive at the harbour more easily.
- The high tides also help in fishing. Many more fish come closer to the shore during the high tide. This enables fishermen to get a plentiful catch.
- The rise and fall of water due to tides is being used to generate electricity in some places.
5. Why the quality of water is deteriorating?
Answer: Quality of water is deteriorating because
- River water, which is our primary source of water, gets contaminated due to various reasons such as direct disposal of sewage by municipalities, excessive discharge of industrial pollutants, use for daily chores like washing, bathing, livestock bathing, garbage disposal, etc.
- Water sourced from groundwater too has deteriorated due to the excessive use of pesticides & insecticides in agriculture, which seep into the groundwater as well as get washed away into the rivers.
6. Write a short note on Tsunami?
Answer:
- Tsunami is a Japanese word that means “Harbour waves” as the harbours get destroyed whenever there is tsunami.
- An earthquake, a volcanic eruption or underwater landslides can shift large amounts of ocean water.
- As a result a huge tidal wave called tsunami, that may be as high as 15m., is formed. The largest tsunami ever measured was 150m. high. These waves travel at a speed of more than 700 km. per hour.
- The tsunami of 2004 caused wide spread damage in the coastal areas of India. The Indira point in the Andaman and Nicobar islands got submerged after the tsunami.
7. Write a short note on ocean currents?
Answer: (i) Ocean currents are streams of water flowing constantly on the ocean surface in definite directions.
(ii) The ocean currents may be warm or cold. Generally, the warm ocean currents originate near the equator and move towards the poles. The cold currents carry water from polar or higher latitudes to tropical or lower latitudes. The Labrador Ocean current is cold current while the Gulf Stream is a warm current.
(iii) The ocean current influence the temperature conditions of the area. Warm currents bring about warm temperature over land surface. The areas where the warm and cold currents meet provide the best fishing grounds of the world.
(iv) Seas around Japan and the eastern coast of North America are such examples. The areas where a warm and cold current meet also experience foggy weather making it difficult for navigation.
8. What are the major movements of ocean water?
Answer: The movements that occur in oceans can be broadly categorised as: waves, tides and currents.
Waves: When the water on the surface of the ocean rises and falls alternately, they are called waves. Waves are formed when winds scrape across the ocean surface. The stronger the wind blows, the bigger the wave becomes.
Tides: The rhythmic rise and fall of ocean water twice in a day is called a tide. It is high tide when water covers much of the shore by rising to its highest level. It is low tide when water falls to its lowest level and recedes from the shore. The strong gravitational pull exerted by the sun and the moon on the earth’s surface causes the tides.
Ocean Currents: Ocean currents are streams of water flowing constantly on the ocean surface in definite directions. The ocean currents may be warm or cold. Generally, the warm ocean currents originate near the equator and move towards the poles. The cold currents carry water from polar or higher latitudes to tropical or lower latitudes. The Labrador Ocean current is cold current while the Gulf Stream is a warm current.