Which alloy contains a non-metal?

Flux is used to remove..........

Consider the following statements:
$(a)$ When the lead-silver alloy is rich in silver,lead is removed by the cupellation process.
$(b)$ Froth flotation can be applied for non-sulphide ores also using a suitable activator.
$(c)$ $PbSO_4 + H_2SO_4$ electrolyte is used for the refining of $Pb$ by electrolysis.
$(d)$ Any metal will not reduce the oxide of other metals which lie above it in the Ellingham diagram.
Using $'T'$ for true and $'F'$ for false statements in the given sequence,select the correct set of code.

For the following statements,mark $T$ for true and $F$ for false statement.
Statement $1$: $SnO_2 +$ wolframite,in this $SnO_2$ is magnetic while wolframite is non-magnetic in nature.
Statement $2$: Argentite ore is concentrated by froth floatation method.
Statement $3$: Copper and lead ores are reduced by self-reduction method.
Statement $4$: In metallurgy of $Fe$,$CO$ is used as a reducing agent at low temperature.

Which of the following is correct?

Brass is an alloy of copper and ......... .