Q70. What are the advantages and disadvantages of firewood?
Q71. What are the advantages and disadvantages of wind energy?
Q72. Give five ways in which you can save energy at home.
Q73. Distinguish between Conventional and non-conventional sources of energy.
Q74. Distinguish between Biogas and natural gas.
Q75. Name and describe briefly methods of extraction.
What are the different methods of mineral extraction?
How are minerals extracted from the Earth?
Give a brief note on mining.