Which one of the following organizations' iron and steel plant was built to use charcoal as a source of power,to start with,but later switched over to hydroelectricity?

Extraction of aluminium from bauxite ore,reduction is carried out by

The extraction of aluminum from its oxide $(Al_2O_3)$ is done by:

Statement $I :$ Leaching of gold with cyanide ion in absence of air $/$ $O_2$ leads to cyano complex of $Au(III)$.
Statement $II :$ Zinc is oxidized during the displacement reaction carried out for gold extraction.
In the light of the above statements,choose the correct answer from the options given below.

Thermite is a mixture of $X$ parts of ferric oxide and $Y$ parts of aluminium powder. $X, Y$ respectively are

Native silver metal forms a water soluble complex with a dilute aqueous solution of $NaCN$ in the presence of