Asbestos used in -

Ans. is 'c' i.e., Cement production o Asbestos is the commercial name given to certain types of fibrous material.o They are silicates of varying composition; the silica is combined with such bases as magnesium, iron, calcium, sodium and the aluminium.o Asbestos is of two tvpes-serpentine or chrysolite variety and the amphibole type.o Ninety per cent of the world's production of asbestos is of the serpentine variety', which is hydrated magnesium silicate, the amphibole type contains little magnesium.o The amphibole type occurs in different varieties, e.g., crocidolite (blue), amosite (brown), and anthrophyllite (white),o Asbestos fibres are usually from 20 to 500 p in length and 0.5 to 50 p in diameter.o Asbestos is used in the manufacture of asbestos cement, fire-proof textiles, roof tiling, brake lining, gaskets and several other items.o Asbestos is mined in Andhra Pradesh (Cudappah), Bihar, Jharkhand, Karnataka, and Rajasthan - but most of it is imported from USSR, Canada. US and South Africa.