Q3.
Write geograhical term for the following:-
1x10=10
1.
Weathering takes place due to temperature and moisture.
2.
Protecting the soil
3.
The temperate grassland of Africa from Botswana.
4.
Backbone of modern industry
5.
Discharge of harmful products from industry
6.
Best quality coal
7.
The coal brown in colour
8.
The aboriginal name of Ayer rock
9.
The mountains island of Australia
Answers
. Short Answer Questions.
Question 1.
What is weathering ?
Answer:
Weathering involves disintegration or decay of solid rock due to change in temperature and weather and their impact on the composition of rock.
Question 2.
Give one point of difference between physical and chemical weathering.
Answer:
Physical weathering does disintegration of rock without chemical reaction and the chemical weathering does change in chemical compounds within rock.
Question 3.
What is known as exfoliation ? Name the processes involved in it ?
Answer:
Sudden change in temperature causes fissures in the rocks through which water penetrates to motivate chemical weathering along with sudden contraction and expansion due to change in temperature peels out the upper layer of rock known as exfoliation.
Question 4.
Name the four processes involved in chemical weathering.
Answer:
These are solution, carbonation, oxidation and hydration.
Question 5.
What is known as oxidation ?
Answer:
It is the process of reaction of minerals present in rocks to atmospheric oxygen.
Question 6.
Briefly describe biological weathering.
Answer:
Biological weathering is done by animals, insects plants and man, because these break up the rocks through making holes, root channels and construction of building, canals etc.
Question 7.
What are exogenic forces ?
Answer:
These are the external forces that sculpture the surface features of the land.
Question 8.
What is called denudation ? Name the processes involved in it.
Answer:
Denudation is the wearing away of landmass by various agents as water, wind and ice through various processes like weathering, mass movement, erosion and transportation.
Question 9.
Name the two processes of gradation.
Answer:
Two processes are denudation and aggradation.
Question 10.
What is the chief characteristic of weathering in tropical climates ?
Answer:
Tropical climates are noted for distinct dry and wet season and high rate of evaporation. During rainy season the oxides of iron and aluminium are dissolved in water and mix up with the soil to form laterite soils.
Question 11.
What is known as mass wasting ?
Answer:
The movement of loose material derived from the bed rock through weathering is called mass wasting.
Question 12.
Name any two slow movements of mass wasting.
Answer:
Slow movements of mass wasting an be divided into two
main types — Creep and Solifluction.
Creep : The slow downhill movement of debris is called soil creep.
Solifluction : The water mixed with soil forms clay which moves as a thick viscous fluid.
Question 13.
Give one example of rapid mass movement.
Answer:
Rapid mass movement includes large amount of debris, soil, boulders and rock pieces etc, e.g. landslides and sheet erosion or displacement of the upper rock strata in large amount to uncover the rocks lying below.
Question 14.
What is known as Sheet Wash ?
Answer:
It is the rapid movement of rock debris etc in heavy amount taking the form of a thick sheet of thick fluid of soil and clay removing settlement and vegetation cover, too.
II. Give a technical term for each of the following :
Question 1.
Disintegration or decomposition of rock.
Answer:
Weathering.
Question 2.
Peeling off of the outer layer of rock through contraction and expansion.
Answer:
Exfoliation
Question 3.
Expansion of minerals in rocks on coming into contact with rainwater.
Answer:
Hydration.
Question 4.
The leveling of land surface by erosion and deposition.
Answer:
Gradation.
Question 5.
The process in which a landform of lower level is upgraded to a higher level.
Answer:
Aggradation.
III. Say whether the following are ‘True’ or ‘False’.
1. Temperature is not a factor in physical weathering.
Answer. False
2. In dry climates mechanical weathering is dominant.
Answer. True
3. In Polar regions there is no chemical weathering.
Answer. True
4. External forces are engaged only in erosion.
Answer. False
5. Shear plane is the surface on which movement of a landslide takes place as a result of its breaking off.
Answer.True