Explain flow of charges inside a wire.
Whenever we apply a potential difference across a wire an electric field is created in the wire. This electric field makes the free-electron move in the direction opposite to the electric field (this happens because the electron has a negative charge, so it moves in the opposite direction) with a speed called drift speed. As the field is from high potential to low potential, so free electrons in the wire move towards the higher potential. Hence current flows from higher potential to lower potential (opposite to the flow of electrons); as the flow of electrons is the flow of current in opposite direction.
Vd=−eE2m→L