১.৬ চুনাপাথরযুক্ত শিলাস্তরের ওপর নদীর প্রধান ক্ষয় প্রক্রিয়াটি
ক) অবঘর্ষ ক্ষয়খ) ঘর্ষণ ক্ষয়
গ) জলপ্রবাহ ক্ষয় ঘ) দ্রবণ ক্ষয়
Answers
Explanation:
Solution:-
\underline{\boxed{\purple{\sf Multiple \: Choice \: Question's \: answers: - }}}
MultipleChoiceQuestion
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sanswers:−
1) (b) Cement
2) (b) SAIL
(iii) (a) Aluminium
(iv) (b) Electronic
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Answer the following briefly in not more than 30 words.
(i) Manufacturing is the process in which goods are produced in large quantities after processing the various raw materials.
(ii) Three physical factors for the location of the industry are:
Availability of raw material-The location of industrial enterprises is sometimes determined simply by the location of the raw materials. The jute mills in West Bengal, sugar mills in Uttar Pradesh, cotton textile mills in Maharashtra and Gujarat are concentrated close to the sources of raw materials.
Suitable climate- Harsh climate is not much suitable for the establishment of industries. There can be no industrial development in an extremely hot, humid, dry or cold climate.
Availability of water and power supply- Many industries are established near rivers, canals and lakes.Iron and steel industry, textile industries and chemical industries require large quantities of water, for their proper functioning.Coal, mineral oil and hydro-electricity are the three important conventional sources of power. Most of the industries tend to concentrate at the source of power.
(iii) Three human factors for the location of industry are
Availability of cheap labour- Labour supply is important in two respects (a) workers in large numbers are often required; (b) people with a skill or technical expertise are needed.
Availability of services such as consultants and financial advice.
Availability of Market-The entire process of manufacturing is useless until the finished goods reach the market. Nearness to market is essential for quick disposal of manufactured goods. It helps in reducing the transport cost and enables the consumer to get things at cheaper rates.
(iv) Basic industries are those which supply their raw materials to industries which manufacture other goods. An example is the iron and steel industry which supplies steel to the automobile industry.
(v) The important raw materials used in the manufacturing of cement are limestone, silica, alumina and gypsum.
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Write the answers of the following questions in 120 words.
(i) Integrated Steel Plants are large plants which handle everything in one complex – from putting together raw material to steelmaking, rolling and shaping.
Mini Steel Plants are smaller, have electric furnaces, use mainly steel scrap and sponge iron as inputs. They have re-rollers that use steel ingots as well. They produce mild and alloy steel of given specifications.
Problems of Steel Industry:
High costs and limited availability of cooking coal.
Lower productivity of labour.
Irregular supply of power.
Poor infrastructure.
Following are some recent developments that have led to a rise in the production capacity:
Liberalisation
Foreign direct investments (FDI) with the efforts of private entrepreneurs.
Improvement in the production process by the use of newer technologies.
(ii) Industries are responsible for four types of pollution – air, water, land and noise pollution. Following are the various reasons:
Air pollution is caused by the presence of a high proportion of undesirable gases, such as sulphur dioxide and carbon monoxide.
Water pollution is caused by organic and inorganic industrial wastes and effluents discharged into rivers.
Thermal pollution of water occurs when hot water from factories and thermal plants are drained into rivers and ponds before cooling.
Wastes from nuclear plants cause cancer, birth defects and miscarriages.
Dumping of wastes especially, glass, harmful chemicals, industrial effluents, packaging, salts and other garbage renders the soil useless.
Noise pollution is caused due to industrial and construction activities, factory equipment, generators, electric saws, drills and other machinery.
(iii) The steps to be taken to minimise environmental degradation by industry are:
To control water pollution, industrial effluents need to be treated on all three levels (primary, secondary and tertiary); the use of water for processing should be minimised via reuse and recycling; rainwater can be harvested to meet water requirements, and groundwater usage should be regulated by law.
For the minimisation of air pollution, smokestacks should be fitted to factories with electrostatic precipitators, fabric filters, scrubbers and inertial separators. Also, smoke can be reduced by using oil or gas instead of coal.
Noise pollution can be controlled by fitting generators with silencers, redesigning machinery to reduce noise, and using earplugs and earphones besides other noise absorbing material.