Here's why:
* Electric Dipole Moment: An electric dipole moment is a vector quantity representing the separation of positive and negative charges in a system. It points from the negative charge to the positive charge.
* Axial Line: The axial line is the line passing through the center of the dipole and perpendicular to the line joining the two charges.
* Electric Field Strength: The electric field strength at a point on the axial line is due to the combined effect of both charges. The field lines originate from the positive charge and terminate at the negative charge.
Since the electric dipole moment points from the negative charge to the positive charge, and the electric field lines also point from the positive to the negative charge, both vectors are aligned in the same direction on the axial line. Therefore, the angle between them is 0 degrees.
