Q1Electrical Materials
Question
2 marks
Q.1. Write the unit of electrical and thermal conductivity.
Answer
Electrical conductivity is measured in siemens per meter (S/m, or mho/m); thermal conductivity is measured in watts per meter-kelvin (W/m·K).
The SI unit of electrical conductivity (σ) is siemens per meter (S/m), equivalently mho/m or Ω⁻¹m⁻¹, quantifying how readily a material conducts electric current. The SI unit of thermal conductivity (k) is watts per meter-kelvin (W/m·K), quantifying the rate of heat conduction per unit area per unit temperature gradient. In metals the two are linked by the Wiedemann-Franz law (k/σT = constant), since the same free electrons carry both charge and heat.