Ferrous Minerals: Ferrous minerals account for about three-fourths of the total value of the production of metallic minerals. They provide a strong base for the development of metallurgical industries. India exports substantial quantities of ferrous minerals after meeting her internal demands. (b) Non-ferrous Minerals: India’s reserves and production of non- ferrous minerals is not very satisfactory. However, these minerals, which include copper, bauxite, lead, zinc, and gold, play a vital role in a number of metallurgical, engineering, and electrical industries. Let us study the distribution of copper and bauxite. Conventional Sources of Energy: Conventional source of energy has been used since the early times. Coal, Petroleum, natural gas, hydroelectricity, thermal power are the source of energy. All conventional sources of energy except hydro-electricity are exhaustible. These sources cause environmental pollution. These sources require huge capital. Non-Conventional Sources of Energy: Non- the conventional sources of energy have come into use only recently. Wind energy, solar energy, tidal energy, geothermal, biogas are examples of these sources of energy. Most of the non- conventional sources of energy are inexhaustible. These sources do not cause environmental pollution. Small amount of money is sufficient to have these sources.