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Q29 (CAPF/2013) Science & Technology › Basic Science (Physics, Chemistry, Biology) › Applied everyday chemistry Answer Verified

The filament of electric bulb is generally made of tungsten because

Result
Your answer:  ·  Correct: D
Explanation

Tungsten is used almost exclusively for the filaments of electric bulbs because it possesses the highest melting point of all metals, approximately 3,422°C [1]. In an incandescent bulb, the filament must be heated to extremely high temperatures to glow and produce visible light [3]. Most other metals would melt or evaporate rapidly at these temperatures, but tungsten's high melting point and low vapor pressure allow it to remain stable and maintain its structural integrity while emitting light. Additionally, tungsten has high tensile strength and stable electrical conductivity, making it ideal for being drawn into the thin, durable wires required for bulb filaments. While alloys are used in other heating devices to prevent oxidation, tungsten's unique thermal properties make it the standard choice for incandescent lighting [1].

Sources

  1. [1] Science , class X (NCERT 2025 ed.) > Chapter 11: Electricity > Activity 11.3 > p. 179
  2. [3] https://www.sciencedirect.com/topics/engineering/filament-lamp
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