The major components in "Gun Metal" are

Which of the following is a non-ferrous alloy?

Which of the following is not a basic flux?

In the wrought iron of the iron pillar located in Delhi,what other elements are present besides iron?

Given below are two statements:
Statement $I$: During electrolytic refining,the pure metal is made to act as anode and its impure metallic form is used as cathode.
Statement $II$: During the Hall-Heroult electrolysis process,purified $Al_2O_3$ is mixed with $Na_3AlF_6$ to lower the melting point of the mixture.
In the light of the above statements,choose the most appropriate answer from the options given below:

Give the correct order of initials $T$ or $F$ for following statements. Use $T$ if statement is true and $F$ if it is false.
$(i)$ Every mineral is an ore but every ore is not a mineral.
$(ii)$ Slag is a product formed during the extraction of metal by the combination of flux and impurities.
$(iii)$ Highly pure metals can be obtained by zone refining.
$(iv)$ Carnallite is an ore of magnesium and sodium.