To prevent magnesium from oxidation in the electrolytic extraction process,which of the following is done?

Thermite is a mixture of iron oxide and which of the following?

In the electrolytic extraction of aluminium,cryolite is used:

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R).$
Assertion $(A):$ Aluminium is extracted from bauxite by the electrolysis of a molten mixture of $Al_2O_3$ with cryolite.
Reason $(R):$ The oxidation state of $Al$ in cryolite is $+3$.
In the light of the above statements,choose the most appropriate answer from the options given below:

Carbon cannot reduce $Fe_2O_3$ to $Fe$ at a temperature below $983 \ K$ because

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?