A small hydroelectric generator is installed on a fast-flowing river to provide electricity for a farm.
The decrease in mechanical energy of the water passing through the turbine is 11500 J11500\text{ J}11500 J every second. The electrical output of the generator is 16 A16\text{ A}16 A at 230 V230\text{ V}230 V.
Calculate the efficiency of the turbine and generator.
When the electrical energy generated is not immediately required, it is used to pump water up to a reservoir on a nearby hill. State the term used to describe the primary form of energy stored by the water in this reservoir.
The use of hydroelectric schemes on a large scale has environmental and economic impacts. Describe one environmental impact and one economic impact.
533 exam-style questions on CIE IGCSE Physics 1.7 Energy, work and power, covering 1.7.1a Energy stores and energy transfers, 1.7.1b Conservation of energy, 1.7.1c Kinetic and gravitational potential energy, 1.7.2 Work done, 1.7.3 Energy resources, 1.7.3a Energy resources and electricity generation, 1.7.3b Nuclear fusion as an energy source, 1.7.3c Efficiency of energy transfer, and 1.7.4 Power. Each one has a worked solution and a mark scheme showing where the marks go.