Physics Group - II (3110018)

BE | Semester-1   Winter-2019 | 02-01-2020

Q2) (b)

The thermal and electrical conductivity of Cu at 20°C Kare 390 W m-1 K-1 and 5.87 x 107 (Ω m)-1 respectively. Calculate the Lorentz number.

Thermal conductivity (K) = 390 W m-1 K-1

Electrical conductivity (σ) = 5.87 x 107 Ω m-1

Temperature (T) = (273 + 20) = 293 K

As we know, Kσ=L T 

 L = Kσ T

L = 3905.87×107293

L = 2.87 × 108 W Ω K-2

Lorentz number L= 2.87 × 108  W Ω K-2