State and explain Biot-Savart Law.
The Biot Savart Law is used to determine the magnetic field intensity B near a current carrying conductor in terms of magnetic field intensity generated by its source current element.
Consider a wire carrying an electric current I and also consider an infinitely small length of a wire dl at a distance r from point A.
Biot Savart Law states that magnetic intensity dB at a point A due to current I flowing through a small element dl is
a) Directly proportional to current (I)
b) Directly proportional to the length of the element (dl)
c) Directly proportional to the sine of angle θ between the direction of current and the line joining the element dl from point A.
d) Inversely proportional to the square of the distance (x) of point A from the element dl.
μ0= Absolute permittivity of air in vacuum
μr= relative permittivity.