A heating element of a heater is made of a material with high resistivity and high melting point. Which of the following material properties is most crucial for its function as a heating element?

Correct option is D

The correct answer is (d) High resistivity.
• A heating element converts electrical energy into heat due to its high electrical resistance.
• Materials like nichrome (80% nickel + 20% chromium) are used because they have high resistivity, high melting point (~1400°C), and oxidation resistance.
Information Booster:
• The heating effect is based on Joule’s Law of Heating (H = I²Rt).
• Nichrome maintains resistance even at high temperatures.
• Common applications: electric irons, toasters, and heaters.
• The material should not oxidize easily when heated.
• High resistivity ensures efficient heating at moderate current levels.
Additional Knowledge:
• Other heating element materials: Kanthal (Fe-Cr-Al alloy), Tungsten (used in bulbs).
• Nichrome wires are often coiled to increase surface area.
• The efficiency of heating elements depends on resistivity and specific heat capacity balance.