Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions

Aman, Aus & Boro are types of which crop?

Which one of the crops is fiber crop?

Robusta, Arabica and Liberica are varieties of ____________.

Identify the crop that does not grow under dryland farming.

Jowar is also known as ____________.

What kind of cotton ‘Narma’ is?

What variety of coffee India grow for the international market?

Land degradation is not the result of ______.

The wasteland in India covers ______.

Jhabua district is located in ______.

Which one of the following is a region of commercial grain farming practiced in South American?

The largest country in Asia Continent in terms of area ______

The two important indices for measuring human development ______ 

In which of the following regions the oldest and well developed urbanized settlements are found?

Which of the following options, represent the correct order of states according to the population?

The second largest country in Asia Continent in terms of area ______

Depending on the mode of occurrence and the nature of the ore, mining is of two types: Surface and underground mining. Surface mining is also known as open cast mining is the easiest and the cheapest way of mining minerals that occur close to the surface, overhead costs such as safety precautions and equipment are relatively low in this method. The output is both large and rapid. When the ore lies deep below the surface, an underground mining method (shaft method) has to be used. In this method, vertical shafts have to be sunk, from where underground galleries radiate to reach the minerals. Minerals are extracted and transported to the surface through these passages. It requires specially designed lifts, drills, haulage, vehicles, ventilation system for safe and efficient movement of people and materials. This method is risky. Poisonous gages, fires, floods, and cave-in bad to fatal accidents. The developed economies are retreating from mining, processing, and refining stages of production due to high labour costs, while the developing countries with large labour forces and striving for a higher standard of living are becoming more important. Several countries of Africa and a few of South America and Asia have over fifty per cent of the earnings from minerals alone.

Opencast mining is used for the minerals which ______

Depending on the mode of occurrence and the nature of the ore, mining is of two types: Surface and underground mining. Surface mining is also known as open cast mining is the easiest and the cheapest way of mining minerals that occur close to the surface, overhead costs such as safety precautions and equipment are relatively low in this method. The output is both large and rapid. When the ore lies deep below the surface, an underground mining method (shaft method) has to be used. In this method, vertical shafts have to be sunk, from where underground galleries radiate to reach the minerals. Minerals are extracted and transported to the surface through these passages. It requires specially designed lifts, drills, haulage, vehicles, ventilation system for safe and efficient movement of people and materials. This method is risky. Poisonous gages, fires, floods, and cave-in bad to fatal accidents. The developed economies are retreating from mining, processing, and refining stages of production due to high labour costs, while the developing countries with large labour forces and striving for a higher standard of living are becoming more important. Several countries of Africa and a few of South America and Asia have over fifty percent of the earnings from minerals alone.

Which method of mining is very risky?

Depending on the mode of occurrence and the nature of the ore, mining is of two types: Surface and underground mining. Surface mining is also known as open cast mining is the easiest and the cheapest way of mining minerals that occur close to the surface, overhead costs such as safety precautions and equipment are relatively low in this method. The output is both large and rapid. When the ore lies deep below the surface, an underground mining method (shaft method) has to be used. In this method, vertical shafts have to be sunk, from where underground galleries radiate to reach the minerals. Minerals are extracted and transported to the surface through these passages. It requires specially designed lifts, drills, haulage, vehicles, ventilation system for safe and efficient movement of people and materials. This method is risky. Poisonous gages, fires, floods, and cave-in bad to fatal accidents. The developed economies are retreating from mining, processing, and refining stages of production due to high labour costs, while the developing countries with large labour forces and striving for a higher standard of living are becoming more important. Several countries of Africa and a few of South America and Asia have over fifty percent of the earnings from minerals alone.

Developed economies are retreating from mining, processing, and refinery stages of production because ______

Depending on the mode of occurrence and the nature of the ore, mining is of two types: Surface and underground mining. Surface mining is also known as open cast mining is the easiest and the cheapest way of mining minerals that occur close to the surface, overhead costs such as safety precautions and equipment are relatively low in this method. The output is both large and rapid. When the ore lies deep below the surface, an underground mining method (shaft method) has to be used. In this method, vertical shafts have to be sunk, from where underground galleries radiate to reach the minerals. Minerals are extracted and transported to the surface through these passages. It requires specially designed lifts, drills, haulage, vehicles, ventilation system for safe and efficient movement of people and materials. This method is risky. Poisonous gages, fires, floods, and cave-in bad to fatal accidents. The developed economies are retreating from mining, processing, and refining stages of production due to high labour costs, while the developing countries with large labour forces and striving for a higher standard of living are becoming more important. Several countries of Africa and a few of South America and Asia have over fifty percent of the earnings from minerals alone.

For which reasons fear of fatal accidents remain in underground mining?