Q20. What are the processes that create different landforms on
the surface of the earth?
process of erosion and deposition create different landforms on the surface of
Q21. Define the term focus and epicenter.
The place in the crust where the movement starts is called the focus. The place
on the surface above the focus is called the epicentre.
Q22. Why are the flood plains very fertile?
flood plains are very fertile because these plains are formed by the fine soil
and sediments brought by the flood water.
Q23. What is a delta?
delta is a feature formed when rivers drop off sediments in low-lying areas,
usually as they enter the ocean, sea or an estuary. It is sometimes shaped like
Q24. How does waterfall form?
The running water in the river erodes the landscape. When the river tumbles at
steep angle over very hard rocks or down a steep valley side it forms a
Q25. What are some other methods used to predict an earthquake?
common earthquake prediction methods adopted locally by people include studying
animal behaviour; fish in the ponds get agitated, snakes come to the surface.
Q26. What are earthquakes?
When the Lithospheric plates move, the surface of the earth vibrates. The
vibrations can travel all-round the earth. These vibrations are called
Q27. What are sand dunes?
the wind blows, it lifts and transports sand from one place to another. When it
stops blowing the sand falls and gets deposited in low hill – like structures. These
are called sand dunes.
Q28. What are the three types of earthquake waves?
are three types of earthquake waves:
P waves or longitudinal waves
S waves or transverse waves
L waves or surface waves
Q29. Name some waterfalls.
highest waterfall is Angel Falls of Venezuela in South America. The other
waterfalls are Niagara Falls located on the border between Canada and USA in
North America and Victoria Falls on the borders of Zambia and Zimbabwe in
Q30. What are exogenic and endogenic forces?
Exogenic forces - The forces that work on the surface of the earth are
called as Exogenic forces.
forces - The forces which act in the interior of the earth
are called as Endogenic forces.
Q31. How are flood plains formed?
At times the river overflows its banks. This leads to the flooding of the neighbouring
areas. As it floods, it deposits layers of fine soil and other material called
sediments along its banks. This leads to the formation of a flat fertile flood plain.
Q32. What are ox bow lakes?
to continuous erosion and deposition along the sides of the meander, the ends
of the meander loop come closer and closer. In due course of time the meander
loop cuts off from the river and forms a cut-off lake, also called an ox-bow
Q33. Why some rocks have a shape of a mushroom?
Winds erode the lower section of the rock more than the upper part. Therefore,
such rocks have narrower base and wider top which resembles a mushroom. These
in the shape of a mushroom, commonly called mushroom rocks.