The SI unit of thermal conductivity (k) is Watt per meter-Kelvin (W/(m·K)) or W·m⁻¹·K⁻¹. This unit comes from Fourier's law of heat conduction, which states that the rate of heat flow (Q) is proportional to the area (A), the temperature gradient (dT/dx), and the thermal conductivity (k): Q = -k A (dT/dx). Rearranging for k, k = Q / (A (dT/dx)). The units are W / (m² (K/m)) = W / (m K) = W m⁻¹ K⁻¹. Assuming the symbols in option A represent W m⁻¹ K⁻¹, it is the correct unit.
Which one of the following is the SI unit of the thermal conductivity of a material?
Asked in UPSC NDA 2 2015 · Topic: Measurement/Unit (Derived Units and their Expression)
More Physics questions
- In SI unit of force ‘Newton’ (N) is given by (where m stands for metre and s stands for second):
- One kilowatt hour is equal to
- Which one of the following statements is not correct ?
- The symbol of SI unit of inductance is H. It stands for
- Which one of the following is NOT the unit of energy ?
- The S.I unit of gravitational constant G is
- Dioptre is the SI unit of :
- Match List–I with List–II and select the correct answer using the code given below the lists : List–I List–II (a) Wavelength 1. Hertz (b) Energy 2. Angstrom (c) Intensity of sound 3. Joule (d) Frequency 4. Decibel