A charge of 1 coul. 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 "radian/sec"`. Find the magnetic field at a point on the axis ofrotation at a distance of 0.8 from the centre of the path. Now half of the charge is removed from one end and placed on the other end. The rod is rotated in a vertical plane about horizontal axis passing through the mid-point of the rod with the same angnlar frequency. Calculate the magnetic field at a point on the axis at a distance of 0.4m form the centre of the rod.
