CBSE: Check NCERT based important extra questions & answers of CBSE Class 9 Science (Chapter 14 - Natural Resources). These questions and answers are important for the preparation of the upcoming CBSE Class 9 Science Exam 2020-21. These questions can be asked in the exam with slight modifications.
CBSE Class 9 Science Exam 2020-21: NCERT Based Important Extra Questions (With Answers) Chapter 14 - Natural Resources
Question: Fill in the blanks
Rainfall patterns depend on the prevailing _____ patterns in an area.
Rainfall patterns depend on the prevailing wind patterns in an area.
Question: The two forms of oxygen found in the atmosphere are
(a) water and ozone
(b) water and oxygen
(c) ozone and oxygen
(d) water and carbon-dioxide
(c) ozone and oxygen
Question: One of the following processes is not a step involved in the water-cycle
operating in nature
Question: Write three ways through which we prevent the loss of topsoil?
Loss of topsoil can be prevented by
(i) checking the falling of trees
(ii) increasing the vegetational cover
(iii) by preventing excessive grazing by animals
Question: Why does the percentage of gases like oxygen, nitrogen and carbon dioxide
remain almost the same in the atmosphere?
It is because cycling of these gases maintains consistency.
Question: Why does Mathura refinery pose problems to the Taj Mahal?
Mathura refinery releases toxic gases (like oxides of sulphur) which causes acid rain and hence corrosion of the marbles of Taj Mahal.
Question: In coastal area, wind current moves from the sea towards the land during
day; but during night it moves from land to the sea. Discuss the reason.
Air above the land gets heated quickly during the day and starts rising. This creates a region of low pressure as a result air over sea rushes into this area of low pressure. This movement of air from one region to the other creates winds. During night, as water cools down slowly, the air above water is warmer than the air on land. So air moves from land to sea creating winds.
Question: The process of nitrogen-fixation by bacteria does not take place in the presence of
(a) molecular form of hydrogen
(b) elemental form of oxygen
(d) elemental form of nitrogen
(b) elemental form of oxygen.
Question: If there were no atmosphere around the earth, the temperature of the earth will
(b) go on decreasing
(c) increase during the day and decrease during the night
(d) be unaffected
(c) increase during the day and decrease during the night.
Question: What is the main cause of wind?
Uneven heating of air over land and water-bodies causes winds.