(i) Heavy electrical industries manufacture equipment used for power generation, transmission and utilization.
(ii) Turbines for steam and hydro power plants, boilers for thermal power plants, generators, transformers, switch gears etc. are the chief products of this industry.
(iii) The most important company in the field of heavy electrical is Bharat Heavy Electricals Ltd (BHEL). It has its plants at Hardwar, Bhopal, Hyderabad, Jammu, Bengaluru, Hansi and Tiruchirappalli.

Tamil nadu produces about 5% of the total thermal electricity produced in India.
(i) Neyveli
(ii) Mettur
(iii) Thoothukudi and
(iv) Ennore (Chennai) are the important thermal power stations in Tamil nadu.

(i) Gypsum is a hydrated sulphate of calcium which occurs as white, opaque or transparent minerals in beds of sedimentary rocks such as limestone, sandstone and shale.
(ii) Gypsum is used in the manufacture of cement, fertilizers, wall board, plaster of paris and in soil conditioning.
(iii) The state of Rajasthan alone accounts for 81% of its reserves. 14% of its reserves is found in Jammu and Kashmir and 2% in Tamil nadu.
(iv) The remaining 3% resources are found in the states of Gujarat, Himachal Pradesh, Karnataka, Uttarakhand, Andhra Pradesh and Madhya Pradesh.

 i) Mica is used in making insulating properties.
 ii) It is used in electrical goods.
 iii) lt is used in making of lubricants, medicines, paints and varnishes.