Assume a solar cell produces 0.5 V at peak sunlight. If a total of 12 V needed, what is the minimum ...

Ans. to #1

Number of cells = 12 V/0.5 V/cell = 24 cells connected in series.

Ans. to #2

A tidal barrage power system consists of a dam that stretches across an estuary, harbor or river that connects to the ocean. When the tides rises, sluice gates open to allow the tidal flow to move through tunnels to fill the area behind the dam. The flowing water produces electricity by spinning a turbine and generator. When the tide reaches its highest level, the gates close capturing the water behind the dam. As the tide drops, water can again flow through the tunnels and produce electricity.

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