NCERT 8th Class (CBSE) Social Science: Minerals and Power Resources

Question: Differentiate between a rock and an ore.

Answer: A rock is an aggregate of one or more minerals. An ore is a rock from which minerals are mined.

Question: Define quarrying.

Answer: Quarrying is a process of extraction in which minerals lying near the surface are simply dug out.

Question: Name the leading tin producers in Asia.

Answer: China, Malaysia and Indonesia are leading tin producers in Asia.

Question: Name two areas in Australia, which have large deposits of gold.

Answer: Two areas in Western Australia having large deposits of gold are Kalgoorlie and Coolgardie.

Question: Name two minerals in whose production India contributes a significant part.

Answer: India has vast deposits of high grade iron ore, and it is also a leading producer of salt.

Question: In which industry is silicon important? From which ore is it obtained?

Answer: Silicon is important in the computer industry. It is obtained from quartz.

Question: Why are minerals considered non-renewable?

Answer: Minerals take thousands of years to form. The rate of formation is much smaller than rate of consumption. So we classify them as non-renewable.

Question: Why is coal called “buried sunshine”?

Answer: Coal is called “buried sunshine” because it is found buried under the earth, and is as important a source of energy as sunshine.

Question: Why are petroleum and its derivatives called “black gold”?

Answer: Petroleum and its derivatives are black in colour but as valuable as gold, so we refer to it as “black gold”.

Question: What is natural gas?

Answer: Natural gas is a fossil fuel obtained with petroleum deposits in oil fields.

Question: Which was the first country to develop hydroelectricity ?

Answer: Norway was the first country to develop hydroelectricity.

Question: Name some important hydel power stations in India.

Answer: Bhakra Nangal, Gandhi Sagar, Nagaijunasagar and Damodar Valley Projects are important hydel power stations in India.

Question: Name nuclear power stations in India.

Answer: Kalpakkam, Tarapur, Ranapratap Sagar, Narora and Kaiga are the nuclear power stations in India.

Question: Give one advantage of biogas over natural gas.

Answer: Biogas is a renewable source of energy whereas the amount of natural gas is limited.