Question

in the electric equipment producing heat e.g. iron, electric heater, etc an alloy such as nichrome is used not pure metals give reason

Answer 1

the alloy nichrome is used in electrical apliances  instead of using pure substance because:-

1:- alloys such as nichrome does not oxidize {burn} even at high temperature.
2:-resistivity of alloys of nichrome are much higher than pure substance

Answer 2

Alloys are used as its resistivity is generally higher than that of its constituent metals. It donot oxidize readily at high temperature while pure metals get oxidize readily. It have high melting point by which it do not melt even when it become red hot