List of top Physics Questions on Electric field and potential due to point

The Young's double slit interference experiment is performed using light consisting of \(480\ \text{nm}\) and \(600\ \text{nm}\) wavelengths to form interference patterns. The least number of the bright fringes of \(480\ \text{nm}\) light that are required for the first coincidence with the bright fringes formed by \(600\ \text{nm}\) light is:

Two-point charges, $q_1 = 36\ \mu\text{C}$ and $q_2 = -9\ \mu\text{C}$ are placed at a distance of $30\text{ cm}$. What distance from $q_1$, where the net electric field is zero, will be: