CBSE Class 7 Social Science Ocean Worksheet

Ocean

Give answer to the following questions approximately in 1- 15 words: -

Question. Why is the ocean water salty?
Ans. Several mineral salts get dissolved in the ocean water. Due to this the ocean water is salty.

Question. Why there is a dense fog near Newfoundland?
Ans. Near the Islands of Newfoundland the warm water of Gulf Stream mixes with the cold water of Labrador. Due to this a dense fog is formed over there.

Question. Explain the route of Gulf Stream current.
Ans. The Gulf Stream starts from the Gulf of Mexico and it reaches to the Islands of Newfoundland.

Question. Write down the main ocean currents of North Atlantic Ocean cycle.
Ans. 1. The Gulf Stream 2. Canary Current
3. Saragasso Sea

Question. What do you understand by Tsunami?
Ans. ‘Tsu’ means coastal and ‘Nami’ means long waves of water. The Tsunami are the long waves of water striking to the coastal areas.

Answer the following questions in approximately 50- 60 words:-

Question. What is the difference between Spring Tide and Neap Tide?
Ans. Spring Tide During the Spring Tide the sun, the moon and the earth all are in a line. The sun and the moon both pull the ocean water jointly.
The rise of water is maximum.
Neap Tide During the Neap Tide the moon, earth and sun are right angles to that of the moon. The sun pulls water to its side and the moon full towards itself. Due to the nearness of the moon the water rises towards moon only.
The rise of water is lower than as usual.

Question. Differentiate between warm water ocean current and cold water ocean current.
Ans. The temperature remains high in Equatorial regions but lower in Polar Regions. The currents going away from the Equator are always warm. Whereas, the currents coming from the poles are always cold.

Question. Why are the ocean currents of Indian Ocean not so definite and systematic?
Ans. The winds in the Indian Ocean are seasonal and change their direction. Due to this, the ocean currents also change their direction. This is the reason the ocean currents of Indian Ocean are not so definite and systematic.

Question. Tide is very useful for ships. How?
Ans. Due to the tide, the deposits of soil against the mouth of the river, washed away. Thus, the soil do not get deposited on the harbours and ships can sail up to a great distance inside.

Question. Why a Spring Tide occurs in full moon and no moon days?
Ans. The sun, the moon and the earth all are in a line during no moon day and full moon day. This is the reason, a spring tide occurs in both these phases.

Question. Why does the Gulf Stream affect the climate of Europe?
Ans. 1. Due to the warm water of Gulf Stream the glaciers moving from the poles melt and do not create obstruction to ships after reaching down.
2. The ports of European countries remain open even in winter season due to its warm water.

Question. What is the difference between the ocean waves and the ocean currents?
Ans. Ocean Waves-The waves arise due to the speed of the wind blowing over the surface of oceans. The water of the oceans always ripples with the winds over the Ocean surface. These are called waves.
Ocean Currents- When the ocean water moves in a particular direction it is called ocean current. The water in the ocean keeps on moving from one place to the other.

Question. Write down a case study of a place that is affected by Tsunami.
Ans. On December 26, 2004, a most powerful Tsunami occurred on the coast of Indian Ocean. This brought devastation in 11 countries. More than 2 lakh people were killed and many more were rendered homeless. Tamilnadu, Kerala, Andhra Pradesh and Pondicherry etc. states suffered the most in India.

Topic : The Medieval World.

Indian history can be divided into three periods – ancient, medieval and modern. Our focus is on medieval history.
The medieval period of Indian history stretches from the 8th century to the 18th century CE. This is further divided into early and later medieval periods.

Major development: - the medieval period was a period of change in every sphere – political, social, cultural, religious and economic.

• Many Rajput kingdom came up.
• India saw many invasions during this period. Mahmud of Ghazni and Mahmud of Ghor plundered India
• The first Muslim empire in India was established Mahmud of Ghor
• The invaders brought new ideas , new religion and new way of thinking.
• The Bhakti and Sufi movement spread in India.
• The Europeans came to trade and gradually established a strong foothold in India.

The history of India has been greatly affected by its geography. India has been known by various names – Aryavarta, Bharatvarsha and Hindustan.

Sources of the medieval period:-
There are two kinds of sources which gives information to reconstruct the past. These are archaeological and literary sources.

Archaeological resources:-
This includes monuments, coins, painting, inscription, and other artefacts.
Monuments: - buildings of historical importance are called monuments. They inform us about the social life religious believes, the culture and the knowledge of science of the people of the period which the monuments where build.
Paintings: - Many styles of painting flouriest during medieval period . Many painting depict the rulers themselves and the court life of the time.
Artefacts: - The object that humans made in the past – pottery, tools, ornaments, metal objects jewelry and weapons are called artifacts.
Coins: - Coins tells about the reigning periods of kings, the economy of the kingdom, the extend of the king empire and about trade with other regions. They give us dates of important political events. A book on coins titled Drarya-Pariksha was written in this period.

Literary sources. :-
Numerous literary work of the time throws light on the life, during the medieval times. Literary sources classified into indigenous and foreign literature.
Indigenous literature: - king, court, poet and scholars wrote extensively and their work throws light on the administration, economy and society of the time .
• Kalhana wrote “the Rajtarangini”.
• Babur wrote “ Bahurnama “ or “Tuzuk-i-baburi”
• Gulbadan begum wrote “the Humayunnama”
• Abul Fazal wrote “Akbarnama’ and “ Ain-i-akbari”
• Prithviraj- raso by Chandbardai describes the life and adventures of the chauhan ruler Prithviraj Chauhan

Foreign literature: - foreign travelers have left interesting accounts of medieval India.
• Alberuni wrote “Ta’rikh al-hind” it gives information on religious , scientific and literary tradition of India.
• Ibn Batata, who wrote the “Rihla”, which give lot of information about the geographical and economic condition of India.
• Marco polo and Nicola conti European traveler visited south India and his book tells us about the customs, lifestyle, and economy of the region.

I. Learn the following terms –

1. Farman- order issued by a king.

2. Travelogue- account written by a traveler visiting a country.

3. Chroniclers- people who maintain a record of events.

4. Inscriptions- records engraved on pillars, stone walls and clay tablets.

5. Numismatic –study of coins as archaeological evidence.

6. Autobiography- account of a person‘s life written by himself/herself.

7. Dynasty – periods of years during which members of a particular family rule a country.

8. Sapt-sindu- the land of seven rivers.

9. Chronology –the order in which events of the past take place.

10 .Archive- a collection of records .

8. Understanding Advertising

Fill in the Blanks:

1. .......... draw our attention to various products and describe them positively so that we become interested in buying them.

2. Advertising is all about building........... 

3. .......... means stamping a product with its particular name or sign.

4. Advertising plays a crucial role of trying to .......... us to buy the products.

5. Advertising of ten show us images of .......... of rich people.

6. Advertising a product costs a lot of .......... 

7. Social advertisement refers to advertisement made by the .......... or .......... that have a larger message for society.

8. Advertisement is an important part of our .......... and  ..........  life today

4. Natural Vegetation And Wild Life

Fill in the blanks:

1. The growth of the Vegetation depends on ............... and ............... 

2.  ............... trees are found in Coniferous Forests.

3. Tropical evergreen forest in Brazil is called the  ............... of the earth.

4.  ............... is one of the worlds largest snakes is found in the tropical rainforest.

5. The grasslands of Brazil is called ............... 

6. The type of natural vegetation found in polar region is  ............... vegetation.

7.  ............... grasslands are found in Venezula.
8.  ............... is a polar animal.

9.  ............... means pure or untouched in the Russian language.

10.  ............... grass land are found in East Africa.