Question of Exercise 1

Mineral and Power Resources of Class 8

Question
Which one of the following is NOT a characteristic of minerals ?

Answer

Option 1 They are created by natural processes.

Option 2 They have a definite chemical composition.

Option 3 They are inexhaustible

Option 4 Their distribution is uneven.

Frequently Asked Questions

What is shifting cultivation What are its disadvantages

Solution:

Shifting cultivation or Slash-and-burn cultivation is generally practiced in dense forest areas. These are  areas with heavy rainfall and rapid vegetation regeneration. Land is wiped out by cutting down trees and burning them. The ashes are then mixed with the earth. After the soil loses  fertility, the land is abandoned and the farmers move to  new plots. 

The main drawback of shifting cultivation is that many trees are cut down in the forest. This increases the fertility of the soil and causes soil erosion.

 

Boojho and Paheli performed experiments taking similar bulbs and cells but two different solutions A and B as shown in Fig.14.1

boojho and paheli performed experiment

They found that the bulb in the setup A glows more brightly as compared to that of the setup B. You would conclude that

(a) higher current is flowing through the circuit in setup A.

(b) higher current is flowing through the circuit in setup B.

(c) equal current is flowing through both the circuits.

(d) the current flowing through the circuits in the two setups cannot be compared in this manner.

 

Solution:

Ans. (a) higher current is flowing through the circuit in setup A.

How was environment treated earlier? What has been the change in perception? Discuss.

Solution:

Answer: The environment was treated as a ‘free’ entity and any industry or individual could pollute the environment without any restrictions. There were very few laws to protect and conserve the environment in India. Government also paid no attention to safeguarding the environment.

Now, there has been a change in perception. Government has introduced various laws to protect and conserve the environment such as Swachh Bahrat Abhiyan. The courts have given out a number of judgments, upholding the right to a healthy environment as intrinsic to the fundamental right to life. Various laws and procedures to check pollution and clean rivers have been formed. The government can also impose a fine on those who pollute our precious environment.

What are the sources of environmental pollution in your area? Discuss with respect to (a) air; (b) water and (c) soil.

 What are the steps being taken to reduce pollution? Can you suggest some other measures?

Solution:

Answer: The various sources of environment pollution in our area are as follows:

(a) Smoke from factories and vehicles run by petrol or diesel are the main reasons behind air pollution.
 
(b) The main cause of water pollution is chemical fertilizers and garbage from factories, farms and houses.
 
(c) Soil is polluted by the pesticides and fertilisers that are used to grow crops or by garbage dumped by human or by factory waste.
 
Steps taken to reduce pollution are:
 
Various laws have been enforced to keep a check on the environment pollution.
Promotion of CNG vehicles to reduce air pollution.
Strict actions against companies who violate environmental laws.
No rules or laws can help make our environment clean and free of pollution, until and unless every individual of the society takes the responsibility on his part to keep their environment clean. Only voluntary actions can make our environment pollution free.

Write a paragraph on the various roles of the government that you have read about in this unit.

Solution:

Answer: The government plays the following roles:

Providing public facilities like healthcare, sanitation and water supply and ensures that these are not overtaken by the private enterprises.
 
Enforcing law against child labour.
 
Fixing minimum wages for workers and revising it from time to time.
 
Enforcing laws regarding safety at the workplace.
 
Enforcing laws regarding the safety of environment.
 
Protecting the interests of consumers against overpricing and standard products.
 
Punishing organisations who do not follow policies to protect the environment against pollution.

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