P2 Revision 5.0 / 5 based on 1 rating ? SciencePhysicsGCSEOCR Created by: syazminCreated on: 16-05-13 21:54 What does a photocell do? A photocell changes light into electricity 1 of 23 How does a photocell work? Photons are absorbed and the energy causes electrons to become free 2 of 23 What kind of electricity does a photocell produce? An electrical current 3 of 23 What is the difference between AC and DC? DC moves in the same direction - AC changes 4 of 23 Advantages of photocells Robust, little need of maintenance, works for a long time, uses renewable energy source and no pollution 5 of 23 Disadvantages of photocells Does not produce electricity when it is dark 6 of 23 What is passive solar heating? Energy trapped from the day is radiated back at night 7 of 23 How do you make an AC generator produce a bigger current? Stronger magnet, more turns on the coil of wire and faster movement of the magnet or coil 8 of 23 Advantage of using wind turbines Produces electricity with no pollution and low maintenance 9 of 23 Disadvantage of using wind turbines Takes up space and relies on good weather 10 of 23 What is the formula for power? Voltage x current 11 of 23 Fossil fuels Coal, oil and gas 12 of 23 Advantages of using fossil fuels Cheap and easy to obtain 13 of 23 disadvantages of using fossil fuels Produces CO2 14 of 23 what is a kilowatt-hour? Unit of electrical energy supplied 15 of 23 What is the formula for efficieny? Useful energy output (100%) /Total energy input 16 of 23 What is the National Grid? Series of transformers and power cables that transport electricity from the power station to the consumer 17 of 23 Forms of biofuels Wood, oil and biodiesel 18 of 23 Nuclear fuel Uranium and plutonium 19 of 23 Advantages of using nuclear power Fossil fuel reserves are not used and there are no greenhouse gases 20 of 23 Disadvantages of using nuclear power Very high maintenance and there are risks of accidents 21 of 23 Precautions when handling radioactive materials Special protective clothing, shielding, use in short time and keep distance 22 of 23 What are the main parts of a power station? Power-transformer-pylons-transformer-home 23 of 23
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