An electric charge \( 10^{-6} \, \mu\text{C} \) is placed at origin \( (0, 0) \, \text{m} \) of \( X - Y \) co-ordinate system. Two points \( P \) and \( Q \) are situated at \( (\sqrt{3}, \sqrt{3}) \, \text{m} \) and \( (\sqrt{6}, 0) \, \text{m} \) respectively. The potential difference between the points \( P \) and \( Q \) will be :