How do we find out the potential difference between two equal and opposite charged (conducting) parallel plates mathematically? Let the charge on a plate be 'Q', Total area of a plate be 'A', the distance between the plates be 'd'. I need a direct mathematical solution please, I've come across various indirect solutions involving the product of the electric field and distance 'd'. The solution may include use of integration explained in detail. Please help me with it. My mind has blown off searching books and internet, always getting indirect solutions.