CBSE Class 6 Social Science Landforms on Earth Worksheet Set 05

Answer: (b) 29 per cent. Land covers about 29 per cent and water about 71 per cent.

Teacher's Note:
1. Oceans cover most of the Earth.
2. Land is the smaller share.

Answer: (c) folding. Internal forces push and bend the crust, producing folds, faults and volcanoes.

Teacher's Note:
1. Erosion and deposition are external processes.
2. Folding happens inside the Earth's crust.

Answer: (b) fold mountains. They were formed when plates collided and the crust folded upwards.

Teacher's Note:
1. The Himalayas are young fold mountains.
2. Collision of plates raised them.

Answer: (c) rift valley. It lies between faults where the land sank.

Teacher's Note:
1. A rift valley forms when land between faults drops.
2. The Narmada flows through it.

Answer: (b) peneplain. A peneplain is formed when erosion wears hills down almost flat.

Teacher's Note:
1. Pene means almost.
2. A flood plain is formed by deposition.

Answer: False. They are formed by movements of the Earth's crust.

Teacher's Note:
1. Tectonic means related to crust movements.
2. Erosion shapes plateaus afterwards.

Answer: True. It was formed by the cooling of lava over a huge area.

Teacher's Note:
1. Basalt rocks cover much of it.
2. Its soil is black and rich.

Answer: True. Water, wind and ice carry away the loosened material.

Teacher's Note:
1. Erosion is an external process.
2. Deposition is the opposite.

Answer: False. It is a river valley carved by the Nile.

Teacher's Note:
1. Glacial valleys are cut by ice.
2. The Nile is a river.

Answer: tectonic plates.

Teacher's Note:
1. The plates move very slowly.
2. Their movement creates mountains and volcanoes.

Answer: valleys. They are often cut by rivers or glaciers.

Teacher's Note:
1. Valleys lie between highlands.
2. Rivers often flow through them.

Answer: Plains. Their flat land and rich soil support farming and settlements.

Teacher's Note:
1. Many early civilisations grew on plains.
2. Flat land also helps in building roads.

Answer: San Andreas Fault. There the plates slide past each other.

Teacher's Note:
1. Strike-slip faults move sideways.
2. The area has frequent earthquakes.

Answer: volcanic islands, formed by lava building up from the sea floor.

Teacher's Note:
1. Hawaii rose from volcanic eruptions.
2. Volcanic islands are built of lava.

Answer: They are known as volcanic mountains, for example Mount Fuji.

Teacher's Note:
1. Lava and ash pile up to make them.
2. Volcanic mountains can be active or dormant.

Answer: A plateau is a large, flat-topped area of land raised above the surrounding land, with steep sides.

Teacher's Note:
1. It is also called a tableland.
2. Plateaus are often rich in minerals.

Answer: Running water, wind, glaciers and waves are external forces that shape the surface.

Teacher's Note:
1. External forces work on the surface.
2. They cause erosion and deposition.

Answer: Peneplains are almost flat plains formed when rivers, wind and ice slowly wear down hills and mountains over a very long time.

Teacher's Note:
1. Peneplain means almost a plain.
2. They are erosional plains.

Answer: A dissected plateau is one that has been cut by rivers and streams into many valleys and ridges.

Teacher's Note:
1. Dissected means cut up.
2. Running water causes the cutting.

Answer: An archipelago is a group or chain of islands close to each other in the sea, such as the Andaman and Nicobar Islands.

Teacher's Note:
1. Many islands lie together.
2. Japan is another example.

Answer: Tiny sea animals called coral polyps live in colonies in warm shallow seas. When they die their hard skeletons pile up over many years to form reefs and islands.

Teacher's Note:
1. Polyps need warm clear water.
2. Lakshadweep consists of coral islands.

Answer: When two parallel faults develop, the block of land between them sinks. This sunken land is a rift valley, such as the Narmada Valley.

Teacher's Note:
1. Rift valleys have steep sides.
2. Land sinks between faults.

Answer: Continental islands are parts of continents cut off by rising seas, such as Sri Lanka. Volcanic islands are formed by volcanic eruptions in the sea, such as Hawaii. Coral islands are built by coral polyps, such as Lakshadweep.

Teacher's Note:
1. Islands differ in how they form.
2. Name one example of each kind.

Answer: Plains support farming, large settlements and transport. Mountains have fewer people, steep land and cooler climate, so people use terraces, herd animals or work in tourism. Plateaus provide minerals and mining work, and coasts allow fishing and trade.

Teacher's Note:
1. Landforms decide work and houses.
2. People adapt to their surroundings.

Answer: Plains have fertile soil, enough water and flat land, so farming is easy and food production is high. They also allow cities, roads, railways and industries to grow.

Teacher's Note:
1. Food surplus helps trade.
2. Easy transport supports industry.