1. Electrical Engineering
Materials
Dr. Md. Sherajul Islam
Associate Professor
EE 3219
Department of Electrical and Electronics Engineering
Khulna University of Engineering & Technology
Khulna, Bangladesh
6. Matthiessen's Rule
An empirical rule which states that the total resistivity of a
crystalline metallic specimen is the sum of the resistivity due to
thermal agitation of the metal ions of the lattice and the resistivity
due to the presence of imperfections in the crystal.
7. There may also be electrons scattering from dislocations
and other crystal defects,as well as from grain boundaries
Resistivity of non pure metals
13. Thermal Conductivity
Thermal conduction in a metal involves transferring energy from the hot
region to the cold region by conduction electrons. More energetic electrons
(shown with longer velocity vectors) from the hotter regions arrive at cooler
regions, collide with lattice vibrations, and transfer their energy. Lengths of
15. Thermal Conductivity
Heat flow in a metal rod heated at one end . Consider
the rate of heat flow, dQ/dt, cross a thin section δx of
the rod. The rate of heat flow is proportional to the
temperature gradient δT/ δx and the cross-sectional
area A.
16. Thermal Conductivity
Fourier's law. The law of heat conduction, also known as Fourier's law,
states that the time rate of heat transfer through a material is
proportional to the negative gradient in the temperature and to the area,
at right angles to that gradient, through which the heat flows.
