What is the difference between the terms overloading and short-circuiting? Why are coils of electric heaters made of an alloy rather than a pure metal?

Explanation

(a) (i) Short-circuiting occurs when a live wire comes in contact with a neutral wire. Overloading occurs when many electrical appliances of high power rating are operated at the same time.
(ii) In short-circuiting, a large current flows through the circuit because the resistance of the circuit formed when two wires touch each other is very small. In overloading, a large amount of current is drawn from the electric supply due to use of many electrical appliances.
(b) (i) The resistivity of an alloy is much higher than that of the pure metal.
(ii) An alloy does not oxidise easily even at high temperatures.