Q39. How are minerals classified on the basis of their composition?
Q40. How is nuclear energy obtained?
Q41. What is an ore? Where are the ores of metallic minerals generally located?
Q42. Why environmental aspects must be carefully looked into before building huge dams?
Q43. Name nuclear power stations in India.
Q44. Why most industries are concentrated around coal mines?
Q45. Which sources of energy would you suggest for
(a) rural areas (b) coastal areas (c) Arid regions
Q46. Write a short note on distribution of minerals in Europe.
Q47. What are the ways to conserve minerals?
Q48. Name the petroleum producing countries in the world.
Q49. What are the advantages and disadvantages of tidal energy?
Q50. Differentiate between a rock and an ore.
Q51. Which one of the following practices will NOT conserve LPG in your Kitchen?
(a) Soaking the dal for some time before cooking it.
(b) Cooking food in a pressure cooker.
(c) Keeping the vegetables chopped before lighting the gas for cooking.
(d) Cooking food in an open pan kept on low flame.