please tell me 20 questions on topic soil class 12
Answers
Answer:
Question 1.
In how many groups the soil has been categorised? Name them.
Answer:
The soil has been categorised into four major groups, i.e.
clay
silt
sand
gravel
Question 2.
Which soil is considered to be the most fertile and used for growing crops?
Answer:
Loamy soil is the most fertile soil and used for growing crops.
Question 3.
Which type of soil absorbs more water but allows less wateMo percolate?
Answer:
Clayey soil absorbs more water but allows less water to percolate.
Question 4.
Give the formula to calculate the absorption percentage.
Answer:
The absorption percentage of water can be calculated by the formula given below
\begin{array}{l}{\text { Percentage of water absorb }} \\ {\qquad=\frac{\text { Amount of water absorbed (in mL) }}{\text { Amount of soil (in gm) }} \times 100}\end{array}
Question 5.
When we add some dry soil to the water in a glass and stir it, bubbles are observed from the soil. What causes these bubbles to raise? [HOTS]
Answer:
When dry soil is added in the water in a glass and stir it, bubbles appear. These bubbles are caused due to the air present in between the soil particles.
Question 6.
What is weathering?
Answer:
Weathering is a natural process by which huge rock is broken down into tiny particles but at a very slow rate.
Question 7.
There is shimmering of air just above the soil during hot summer day. What does the term shimmering indicate? [HOTS]
Answer:
The term shimmering means that the air shines with a slightly shaking light.
Question 8.
Draw a diagram to show the different layers of soil.
Answer:
Soil Class 7 Extra Questions Science Chapter 9 1
Question 9.
Name two soil types used for cultivation.
Answer:
Clayey soil and loamy soil are rich in humus and are suitable for growing plants like wheat and gram.
Question 10.
Soil has particles of different sizes. Arrange the words given below in decreasing order of their particle size. Rock, clay, sand, gravel, silt [NCERT Exemplar]
Answer:
The soil particles with the decreasing order of their particle sizes can be shown as
Rock > gravel > sand > silt > clay
Question 11.
There are two components of soil one that comes from living thing and other from non-living thing. What are these two components?
Answer:
The two major components of soil are weathered rock particles, i.e. non-living components and humus that consists of living organisms like fungi, bacteria, worm, insects, etc.
Question 12.
It is necessary to ban the use of polythene bags and plastics. Do you agree? If yes, why? [HOTS]
Answer:
Polythene bags and plastics pollute the soil as they kill the organisms living in the soil.
That’s why, it is necessary to ban the use of polythene bags and plastics.
Question 13.
List the substances which pollute the soil.
Answer:
The substances which pollute the soil are polythene bags, plastics, waste products, chemicals, pesticides, etc.
Question 14.
A special kind of soil is used for making matkas and surahis. Name it. [HOTS]
Answer:
Clayey soil is used to make matkas and surahis.
Question 15.
Explain the term humus that is generally found in the uppermost layer of soil.
Answer:
The rotting dead matter in the soil is called humus.
Question 16.
Can we make toys with the soil obtained from a field? Explain.
Answer:
No, soil from a field cannot be used to make toys. In order to make toys, the soil should be clayey.
Question 17.
The percolation rate varies from soil to other soil. Which soil would have the highest and least percolation rate?
Answer:
Percolation rate of water is highest in the sandy soil, while the lowest in the clayey soil.
Question 18.
How can a farmer convert acidic soil into neutral soil? [NCERT Exemplar]
Answer:
The farmer can convert acidic soil into neutral soil by adding a small quantity of quicklime or slaked lime solution to the soil.
Question 19.
Do all types of soil absorb water to the same extent? Give reason for your answer.
Answer:
No, it is because different types of soil has different absorbing capacity of water.
Question 20.
For planting rice, which kind of soil would be most suitable?
Answer:
For planting paddy (rice), clayey soil that is rich in organic matter and have a good water retaining capacity is ideal.
Explanation: