Akshat Goenka

Imagine an acid (lets say HCl). They are very happy with each other and stay together in the concentrated form. When you add water (dilute the acid), they weaken the love between the H atom and Cl atom and they eventually separate out as H⁺ & Cl^- ions (because Cl is more electronegative than H).
Now to conduct electricity you need ions and water helps in the production of these ions, which are then responsible for conducting electricity (which is nothing but movement of charge...in this case ions).