Our Changing Earth Class 7 Questions and Answers
Answer the following questions.
Que- Why do the plates move?
because of the movement of the molten magma inside the earth.
Que- What are exogenic and endogenic forces?
The forces that work on the surface of the earth are called exogenic forces while The forces which act in the interior of the earth are called endogenic forces.
Que- What is erosion?
Erosion is the wearing away of the landscape by different agents like water, wind, and ice.
Que- How are flood plains formed?
When a river overflows its banks, it deposits layers of fine soil and other material along its banks. It results in the formation of a flat fertile floodplain.
Que- What are sand dunes?
Sand dunes are the low hill-like structures formed in the desert when wind deposits sand at one place.
How are beaches formed?
Beaches are formed when sea waves deposit sediments along the shoreline
Que- What are oxbow lakes?
Through erosion and deposition along the sides of the meander loop, the ends of the loop come closer and closer to each other, eventually cutting off from the river and forming a “cutoff lake.”called an ox-bow lake.
Tick the correct answer.
Which is not an erosional feature of sea waves?
- Sea cave
The depositional feature of a glacier is:
- Flood plain
Which is caused by the sudden movements of the earth?
- Flood plain
Mushroom rocks are found in:
- River valleys
Ox bow lakes are found in:
- River valleys
Que- Some rocks have a shape of a mushroom.
A windy environment is an active agent for erosion in deserts, which erodes the lower part of rocks more than the upper part. As a result, some rocks have a mushroom-like shape with a narrow base and a wide top.
Que- Flood plains are very fertile.
Due to the fine sediment and fine soil layers deposited along the banks by floods, floodplains are ideal for agriculture.
Que- Sea caves are turned into stacks.
The sea arch is formed when the sea caves become larger and only the roof of the cave remains. As a result, erosion breaks away the roof and just the walls remain. They are called stacks.
Que- Buildings collapse due to earthquakes.
An earthquake travels outward as waves from the epicentre. As the surface vibrates, structures built on the earth’s surface shake, resulting in the collapse of buildings.
Match the Column
|Beach||River of ice|
|Waterfall||Vibrations of earth|
|Hard bed rock|
|Inside Our Earth Class 7 Questions and Answers|
Class 7 Geography Chapter 3 Extra Questions And Answers
The lithosphere is broken into a number of plates known as the Lithospheric plates.
Mass destruction is caused by movements such as earthquakes and volcanoes.
A Volcanoes occur when molten material erupts suddenly from the earth’s crust
The place where movement starts in the crust is called the focus
The epicentre is the area on the surface above the focus.
An earthquake is measured with a machine called a seismograph.
The magnitude of the earthquake is measured on the Richter scale.
A common way to predict earthquakes is by studying animal behavior; fish in the ponds get agitated, snakes come to the surface.
The process of weathering is the breaking up of rocks on the earth’s surface.
The process of erosion refers to the wearing away of landscape by agents such as water, wind and ice.
The process of erosion and deposition on the earth’s surface creates different landforms.
The river twists and turns as it enters the plain, forming large bends called meanders.
The raised banks are called levees.
The erosion and deposition of sea waves result in coastal landforms.
The sediments from all the mouths combine to form a delta.
On the rocks, there are hollow caves that are called sea caves.
Sea cliffs are steep, rocky coasts that rise almost vertically from the sea.
Deserts can have rocks in the shape of mushrooms, called mushroom rocks.
Large deposits of sand are known as loess.
Loess is found in large quantities in China.
There are three types of earthquake waves:
- P waves or longitudinal waves
- S waves or transverse waves
- L waves or surface Waves