Understanding the Concept
* Electric Dipole: An electric dipole consists of two equal and opposite charges separated by a small distance.
* Equatorial Axis: The equatorial axis of an electric dipole is a line perpendicular to the dipole moment vector and passing through the midpoint of the dipole.
* Electric Field: An electric dipole creates an electric field around it. The field lines originate from the positive charge and terminate on the negative charge.
Reason for Zero Work
1. Potential is Constant: The electric potential at all points on the equatorial axis of an electric dipole is constant. This is because the contributions from the positive and negative charges to the potential at any point on the axis cancel each other out.
2. Work and Potential Difference: Work done in moving a charge in an electric field is equal to the product of the charge and the potential difference between the initial and final points. Since the potential is constant along the equatorial axis, the potential difference is zero.
3. Zero Work: Therefore, the work done in moving a test charge 'q' along the equatorial axis of an electric dipole is:
Work = q * (Potential Difference) = q * 0 = 0
In Conclusion
Moving a test charge along the equatorial axis of an electric dipole requires no work because the electric potential remains constant along this axis.
