Current Electricity

• It is the rate of flow of electric charge flowing though any section of wire.

• Electric current flowing through a conductor is directly proportional to the potential difference across the two ends of the conductor; physical quantities such as temperature, mechanical strain, etc. remaining constant.

•   Conductance $G=\frac{A}{\rho l}$
• Electrical conductivity (s) is defined as the reciprocal of resistivity.

 Motion of electrons due to thermal energy
 

• Free electrons are in continuous random motion. They undergo change in direction at each collision and the thermal velocities are randomly distributed in all directions.
• Average thermal velocity,$u=\frac{u_1+u_2+u_3+........+u_n}{n}$ is zero … (1)
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Drift velocity

• $\overrightarrow{v_d}$ is defined as the velocit…