The schematic of hydroelectric plant is shown in Figure. Water from about middle of the total height of the dam is taken to the turbine, as shown by point B in the diagram.

(i) With reference to point B, potential energy of how much water reservoir in the dam will be converted into kinetic energy?
(ii) What will be the effect on electricity generation, if the channel taking water to turbine starts at point A?
(iii) What will be the effect on electricity generation, if the channel taking water to turbine starts at point C?