Tungsten is a pure metal with the highest melting point (3422°C) of all metals, used as the filament in incandescent bulbs. Nichrome is an alloy of nickel and chromium with high electrical resistivity, used in heating elements like toasters and electric irons.
Tungsten: pure metal, melting point 3422°C, resistivity 5.6×10⁻⁸ Ω·m — used in bulb filaments.
Nichrome: Ni-Cr alloy, melting point ~1400°C, resistivity ~110×10⁻⁸ Ω·m — used in heating elements.
Nichrome has ~20× higher resistivity than tungsten.
Tungsten has the highest melting point of all metals.
Nichrome resists oxidation at high temperatures due to Cr₂O₃ layer.
P = I²R — high resistivity of nichrome means more heat for same current.
Property | Tungsten (W) | Nichrome (NiCr) Type | Pure metal | Alloy (Ni 80% + Cr 20%) Melting point | 3422°C (highest of all metals) | ~1400°C Resistivity | 5.6 × 10⁻⁸ Ω·m | ~110 × 10⁻⁸ Ω·m Density | 19.3 g/cm³ | ~8.4 g/cm³ Appearance | Greyish-white, hard metal | Silvery alloy Oxidation | Oxidises if not in inert gas | Resistant to oxidation at high T Thermal conductivity | 173 W/(m·K) — good | ~11 W/(m·K) — low Electrical conductivity | Good conductor | Lower conductivity (high resistance) Atomic number | 74 | — (alloy) Symbol | W (Wolfram) | —
Tungsten: • Incandescent light bulb filaments — due to extremely high melting point, it glows without melting. • Bulbs are filled with inert gas (argon/nitrogen) to prevent oxidation. • X-ray tube targets — high atomic number and melting point. • Welding electrodes (TIG welding). • Rocket nozzle inserts. • Armour-piercing ammunition (tungsten carbide).
Nichrome: • Electric heating elements: toasters, electric irons, room heaters, furnaces. • Resistance wires in laboratories. • Hair dryers and electric kettles. • Wire-wound resistors. • Kilns and industrial furnaces (up to 1200°C).
Key reason for each application: • Tungsten in bulbs: needs to emit white light → must reach ~2500°C → needs very high melting point. • Nichrome in heaters: needs to generate heat efficiently → high resistivity → more heat per unit current (P = I²R).
Why tungsten in bulb filament:
Why nichrome in heating elements:
Resistance comparison: For the same wire dimensions, nichrome has ~20× higher resistance than tungsten. More resistance → more heat generated (P = I²R) for same current.
Tungsten is a pure metal with the highest melting point (3422°C) and is used in bulb filaments. Nichrome is a Ni-Cr alloy with much higher electrical resistivity (~110×10⁻⁸ Ω·m) and is used in heating elements.
Nichrome has ~20× higher resistivity than tungsten, so it generates more heat per unit length for the same current (P=I²R). It also resists oxidation at high temperatures, making it durable.
Tungsten has the highest melting point (3422°C) of all metals. It can withstand the ~2500°C operating temperature while emitting white light. No other metal survives these conditions.
Difference Between Speed and Velocity in Physics
Learn the crucial difference between Speed and Velocity in physics. Understand why speed is a scalar quantity and velocity is a vector quantity that requires direction.
Stefan's Law — Stefan-Boltzmann Law of Radiation
Stefan's Law: P = σAT⁴. Stefan-Boltzmann constant σ = 5.67×10⁻⁸ W/m²K⁴. Power radiated by a black body is proportional to T⁴. Applications and derivation.
Dimensional Formula of Surface Tension
Learn how to derive the dimensional formula of Surface Tension [M1 L0 T-2]. Get step-by-step notes for Class 11 Physics Units and Measurements.
Thermal Capacities of Two Bodies in a Ratio
If thermal capacities of two bodies are in ratio C₁:C₂, then for equal heat supplied, temperature rises are in ratio C₂:C₁. Formula: Q = CΔT where C = mc.
What is Threshold Frequency in Physics?
Learn the definition of Threshold Frequency in the Photoelectric Effect. Understand why no electrons are emitted below this frequency regardless of light intensity.
Turn this guide into revision flashcards, a practice exam, or an AI-generated podcast — free, no signup required.