A charge of `1C` is placed at one end of a non conducting rod of length `0.6m`. The rod is rotated in a vertical plane about a horizontal axis passing through the other end of the rod with angular frequency `10^(4)pi rad//s.` Find the magnetic field at a point on the axis of rotation at a distance of `0.8m ` from the centre of the path.

Explanation

`B=(mu_(0)ir^(2))/(2(r^(2)+x^(2))^(3//2)),i=(qomega)/(2pi),B=(mu_(0))/(2pi)(qomegar^(2))/((r^(2)+x^(2))^(3//2))`