Question

Conductors of electric toasters and electric iron are made of an alloy rather than a pure metal. Why ?

Hint:

Nichrome (Nickel + Chromium) is the most common alloy used for heating elements.

Answer 1

Step 1: Understanding the Concept:
Heating appliances utilize the heating effect of current (\( H = I^2Rt \)), which requires high resistance and durability at high temperatures.
Step 2: Detailed Explanation:
1. High Resistivity: Alloys (like Nichrome) have much higher resistivity than pure metals. This produces a significant amount of heat for a given current.
2. Anti-oxidation: Alloys do not oxidize (burn) easily at high temperatures, whereas pure metals would likely melt or corrode quickly when red hot.
Step 3: Final Answer:
Alloys are used because of their high resistivity and their ability to withstand high temperatures without oxidation.