Understanding the Long Bent Pipe for Water Transfer

The question asks about a specific type of long, bent pipe used to transfer water from a reservoir at a higher elevation to one at a lower elevation, especially when a hill separates them. This setup uses the principle of pressure to move the water. Let's look at the options provided:

• summit: A summit is the highest point of a hill or mountain. It refers to geography, not a pipe used for water transfer.
• syphon: A syphon is a bent pipe or tube used to move a liquid from a higher level to a lower level over an intermediate elevation. It works by creating a partial vacuum at the highest point, allowing atmospheric pressure on the liquid surface in the upper reservoir to push the liquid up and over the hump. This perfectly matches the description given in the question – a long bent pipe carrying water over a hill from a higher reservoir to a lower one.
• spill way: A spillway is a structure built into a dam or reservoir to allow controlled release of water, typically to prevent the reservoir from overflowing. It is not a pipe used to connect two separate reservoirs.
• none of the above: Since 'syphon' correctly describes the device, this option is not applicable.

Based on the definitions and how these structures function, the long bent pipe described is known as a syphon. The syphon allows water to flow uphill to the highest point of the pipe (over the hill) and then downhill to the lower reservoir, powered by the difference in liquid levels and atmospheric pressure. Therefore, the correct term for the described device is a syphon.