Nichrome — typical engineering application Nichrome (a nickel–chromium resistance alloy) is widely used in which of the following applications?

Introduction / Context:
Nichrome is a high-resistance, oxidation-resistant alloy commonly used when heat generation by Joule heating is required. Its material properties make it ideally suited to heating elements in appliances and industrial equipment.

Given Data / Assumptions:

• Nichrome has relatively high resistivity compared to copper or aluminum.
• It withstands high temperatures and resists oxidation in air.
• Mechanical strength remains acceptable at elevated temperatures.

Concept / Approach:
Heater coils require a conductor that maintains stable resistance and structural integrity under red-hot conditions. The alloy’s resistivity enables compact coils; chromium provides oxide scale protection that slows further oxidation; nickel contributes mechanical and corrosion resistance. These features align with heater applications, not with power lines (which need low resistance) or general lamp filaments (typically tungsten).

Step-by-Step Solution:
Identify desired properties: high resistivity, high-temperature oxidation resistance, mechanical stability.Match properties to applications: heating elements need these attributes.Power lines require low resistance → not Nichrome.Lamp filaments mostly use tungsten for high melting point and emissivity.

Verification / Alternative check:
Household toasters, hair dryers, and industrial furnaces use Nichrome wire heating elements, confirming the standard application.

Why Other Options Are Wrong:
Overhead lines emphasize conductivity and low I^2R loss; lamp filaments demand very high melting point and brightness characteristics that tungsten supplies better than Nichrome.

Common Pitfalls:
Assuming any resistive metal suits heating; many oxidize rapidly or creep excessively under heat.

Final Answer:
heater coils