urgent ..please explain with proper steps: a 500uC charge is at the centre of a square of side 10cm. find the work done in moving a charge of 10uC between two diagonally opposite points on the square..

Electric potential by charge 500 μC at the diagonally opposite points on the square is same. 

Therefore the potential difference is zero between the diagonally opposite points on the square. 

Work done = Potential difference x Charge = zero.