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23 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Types of renewable resources |
*Hydroelectricity: generated, flowing rivers or water falling from a dam into the hills *Geothermal energy: heat underground, turn water to steam, steam drives turbines *Biomass |
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Advantages of renewable resources |
*Generating electricity, no pollution *No fuel costs |
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Disadvantages of renewable resources |
*Cost money to build machinery to generate electricity *Wind Turbines spoil the view *Harmful to habitats and wildlife due to tidal barrages and hydroelectric flood valleys *Not available all the time |
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Advantages of fossil fuels |
*Cheaper than using renewable resources *Available all the time |
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Disadvantages of fossil fuels |
*Eventually run out and cannot easily be replaced *Release Carbon Dioxide contributes to climate change *Release Sulfur Dioxide contributes to Acid Rain *Extracting and Transporting fossil fuels causes pollution and change landscape |
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Advantages of Nuclear power |
Do not release Carbon Dioxide or other polluting gases |
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Disadvantages of Nuclear power |
*Uranium used as nuclear fuel will one day run out *An accident in a nuclear power station could affects thousands of people *Power stations have to be safe which costs more money *worried about the probabilities *Produce radioactive waste which stays radio active for millions of years *Radio active waste can damage the environment |
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What is an inducing current |
*If you move part of a loop of wire in a magnetic field *Electrical currently the will flow through the wire *This is called Electromagnetic induction |
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How can you change the direction of the current? |
*Changing the direction of motion of the wire *Changing the direction of the magnetic field |
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How can you increase the size of the current? |
*Moving the wire faster *Using stronger magnets *Using more loops of the wire |
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How do generators work? |
Use very strong magnetic fields, so they usually use electromagnetic instead of permanent magnets |
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What do permanent magnets do in a generator? |
*Produce a magnetic field, the stinger the magnetic field, the greater the current |
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What is the national grid? |
The system of wires that transmit electricity from power stations to the places where the electricity is used. |
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What are transformers, step up transformers and step down transformers used for? |
*Used to change the size of an alternating voltage *Increase the voltage as it leaves the power stations and before the electricity is transmitted *Take electricity from the power lines and reduce it to safer voltages again before it gets to homes |
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Transformer calculations: |
*Voltage (Primary) ÷ Voltage (Secondary) = Turns (Primary) ÷ Turns (Secondary) *Voltage (Secondary) = Voltage (primary) x [ Turns (secondary) ÷ Turns (Primary) ] |
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What us current? |
The amount of Charge flowing past a point each second |
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Power = |
Energy ÷ Time OR Current × Voltage |
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Types of ways to use less energy in homes |
*Use modern light bulbs (10W light output, 20W of energy put in) instead of an old light bulb (10W light output, 100W of energy Input) *Use microwave ovens: cook food quicker, use less energy the a normal oven *Insulate homes: reduces amount of energy lost from homes |
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How do you work out payback time? |
Payback time = Cost of energy saving method ÷ savings per year |
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What are the 9 forms of energy? |
Thermal Light Sound Electrical Kinetic Chemical Nuclear Elastic potential Gravitational potential |
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If an object has a constant temperature it must be... |
Absorbing the same amount of power as it is radiating |
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If an object is warming up then... |
The power absorbed is greater than the power radiated |
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If an object is cooling down then... |
The power absorbed is less than the power radiated |
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