MP Board Class 7th Social Science Solutions Chapter 20 Hydrosphere
MP Board Class 7th Social Science Chapter 20 Text Book Questions
Choose the correct alternatives from the following
The largest ocean in the world is:
(a) Atlantic Ocean
(b) Pacific Ocean
(c) Indian Ocean
(d) Arctic Ocean
(b) Pacific Ocean
The area covered by water on the earth is:
Fill in the blanks:
- The …………. Hemisphere of the earth is a water Hemisphere.
- The deepest trench in die world is …………..
MP Board Class 7th Social Science Chapter 20 Short Answer Type Questions
Write down the names of the oceans of the world.
The oceans of die world are:
- Pacific Ocean
- Adan-tic Ocean
- Indian Ocean
- Arctic Ocean
Write any three advantages of Oceans?
Three advantages of oceans are –
1. Rain on land:
All the rain on land are due to the evaporation of sea water. Rains are useful for vegetation, animal life and human beings.
2. Balance of temperature:
Ocean shelp to maintain balance of temperature on land.
3. Means of transport:
The international trade is possible because of the oceans and seas, which joins the continents.
Why is hydrosphere? Explain.
The part of the surface of the earth which is covered with water is known as hydrosphere. Water makes up 71% of die earth surface and remaining part of 29% is land.
MP Board Class 7th Social Science Chapter 20 Long Answer Type Questions
Explain water cycle through illustrations.
On die surface of the earth rivers, lakes, underground water, ponds, ice-covered area, seas etc. are the sources of water. Water evaporates from these water bodies. The water vapor rises upwards, and forms clouds. The clouds precipitate indie form of rain.
The rain water gets collected in rivers, lakes, ponds and other water bodies. Through rivers, it reaches back to the oceans. In this way water traverses continuously in all spheres, the lithosphere, die atmosphere and the hydrosphere. This process is known as water cycle. In short we can say that the movement of water in hydrosphere, atmosphere and lithosphere is called water cycle.
Describe the different parts of the oceanic floor and draw a well labelled diagram.
The oceanic floor is full of ridges and pits. The depth of the sea is unequal. On the basis of the physical structure, the floor of the oceans are divided into four parts:
1. Continental Shelf:
That part of the sea which touches die land and is generally less deep is called the continental shelf. Its depth in general less than 100 fathoms or 150 meters and its breadth varies form few kilometers to more than 100 kilometers.
2. The Continental slope:
Where the edge of the steeps slope down wards it is called the continental slope. It is deeper than die continental shelf.
3. The Ocean deep plains:
The part of die ocean bed which is deep and plain is called the oceanic deep plains. These plains occupy die most part of the ocean bed.
4. The Oceanic trench or pit:
At the bottom of the sea there are many deep pits. These are known as the oceanic trench.