Subject and UNIT: Physics for Information Science: Unit I: Electrical Properties of Materials
Failures of classical free electron theory is a macroscopic theory.Classical theory states that all free electrons will absorb energy, but quantum theory states that only few electrons will absorb energy.
Subject and UNIT: Physics for Information Science: Unit I: Electrical Properties of Materials
Success of classical free electron theory of metals verifies Ohms law. It explains the electrical and thermal conductivity of metals.
Subject and UNIT: Physics for Information Science: Unit I: Electrical Properties of Materials
The electrical and thermal conductivity decreases with the increase in temperature and impurities.
Subject and UNIT: Physics for Information Science: Unit I: Electrical Properties of Materials
Co-efficient of electrical conductivity is defined as the quantity of electricity flowing per t unit area per unit time maintained at unit potential gradient.
Value, Theory, Law, Proof, Formula
Subject and UNIT: Physics for Information Science: Unit I: Electrical Properties of Materials
Law: The ratio between the thermal conductivity and electrical conductivity of a metal is directly proportional to the absolute temperature of the metal.
Formula, Unit, Equation
Subject and UNIT: Physics for Information Science: Unit I: Electrical Properties of Materials
Let us consider a uniform rod AB with the temperatures T1 (Hot) at end 'A' and T2 (cold) at end B. Heat flows from hot end 'A' to the cold end 'B'.
Definition, Unit, Formula
Subject and UNIT: Physics for Information Science: Unit I: Electrical Properties of Materials
In metals, the conduction takes place not only by thermal motion of free electrons but also by thermally excited lattice vibrations, called phonons.
Definition, Unit, Formula
Subject and UNIT: Physics for Information Science: Unit I: Electrical Properties of Materials
We know in the absence of external electric field, the motion of electrons in a metal moves randomly in all directions.
Subject and UNIT: Physics for Information Science: Unit I: Electrical Properties of Materials
We know in metals the electrical conductivity depends on the number of charge carriers (free electrons) present in the material.
Subject and UNIT: Physics for Information Science: Unit I: Electrical Properties of Materials
After the discovery of electron, Drude and Lorentz attempted for an explanation of electrical and thermal conductivities based on the assumption that metal contains a certain number of free electrons and hence called free electron theory.
Subject and UNIT: Physics for Information Science: Unit I: Electrical Properties of Materials Physics for Information Science
Electrons have similar behaviour in conductors, semiconductors, dielectric, magnetic and super conducting materials.
Subject and UNIT: Physics for Information Science: Unit I: Electrical Properties of Materials Physics for Information Science
Low resistive materials are generally called conducting materials. These materials have high electrical and thermal conductivity.