Why is direction of current opposite to flow of electrons?
Electric current is defined as the rate of transfer of charge. The direction of conventional current is always given by the direction in which positive charge moves. This can be achieved either by moving positive charges in this direction, or by moving negative charges (ie. electrons) in the opposite direction. If you are moving electrons then the side which they are going to becomes negative and the side they are leaving becomes positive. Since direction of current is towards the positive, the current is in the opposite direction to flow of electrons.
