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P3 Science revision flashcards
Cards in this deck (36)
- 1P3: Sustainable EnergyJessica Brown
- 2How is electricity generated?1) Heat is used to boil water (steam)
2) Steam drives the turbine which powers the generators
3) Electricity produced in the generators is sent to step up transformers which then go to a National Grid
4) Electricity is distributed to homes through National Grid at high voltages to reduce energy losses
5) High voltages are stepped down by a transformer to the mains supply voltage in our homes - 3What is the mains supply voltage in our homes?230 V
- 4How is radioactive waste produced through powerstations?The powerstations release energy owing to changes in the nuclei of radioactive substances
- 5What is the danger of radioactive waste?Because it emits ionisng radiation. There is the danger of being exposed to a radiation source outside the body. This is irradiation
- 6What is contammination and how could you get it?It is continously exposing you to dangerous ionising radiation and it can happen through getting radiation on your clothes or it entering your body
- 7Is contamination or irradiation worse? And why?Contamination is a bigger threat because it leads to cell death and cancer
- 8Why are sankey diagrams used?To show the generation/distribution of electricity, including the efficiency of energy transfers
- 9What is renewable energy and give some examplesEnergy which wont contribute to GW such as wind, solar, wave, biofuel, hydroelectric power
- 10Are renewable energy sources primary or secondary energy sources?Primary because they wont run out like fossil fuels
- 11Why is a generator used?To produce electricity when a magnet rotates near a coil (in larger cases its an electromagnet)
- 12What is the relationship between the current supplied by a generator and the amount of primary fuel it uses each second?The greater the current supplied by a generator, the more primary fuel it uses per second
- 13How does a wind turbine provide energy?Wind turns the blades, providing power to the generator
- 14What are is an advantage and disadvantage of wind turbines?They provide free energy as long as the wind is blowing
2) Produces small amounts of electricity so hundreds would need to be built - 15How does a hydroelectric dam provide energy?Water stored in the reservoir flows down pipes and turns the turbines. This powers the generators and produces electricity
- 16What is an advantage and disadvantage of hydroelectric dams?1) Once built they provide large amounts of reliable, cheap energy
2) Large areas may need to be flooded to build hydroelectric stations - 17What happens in the energy change when the generator is driven by the flow of water through turbine blades?1) Water in the reservoir has potential energy
2) Flowing water has kinetic energy (causing blades to rotate)
3) Magnet rotates near a coil in the generator. This changes kinetic energy into electrical energy (This is then transferred to homes via National Grid) - 18What is power?A measure of the rate of energy transfer
- 19What is the equation for potential difference?Power divided by current
- 20What is energy measured in?Joules
- 21What is the energy transfer equation and how else can it be used?Energy transferred = Power x time
It can be rearranged to find power and time - 22What is the equation for Cost of electricity?Total cost = No of units x Cost per unit
- 23What is the equation for efficiency of appliances?Efficiency = (energy transferred divided by total energy supplied) x 100
- 24What is the relationship between the proportion of energy and the efficiency of the appliance?The greater the proportion of energy, the more efficient the appliance is
- 25Why do we need a mix of energy sources?To secure a National energy supply
- 26What factors are considered when choosing an energy source?Efficiency, cost, power output, lifetime and Environmental damage
- 27What are some advantages and disadvantages of fossil fuels? What is the power output?1) High energy output, easily distributed, convenient, efficient
2) Non renewable, contributes to acid rain, fuels damage the Environment, burning generates GHG
POWER OUTPUT IS HIGH - 28What are some advantages and disadvantages of Nuclear? What is the power output?1) Reliable, no GHG, efficient, high energy output
2) Threat of damaging to the Environment, disposal of nuclear waste is difficult
POWER OUTPUT IS HIGH - 29What are some advantages and disadvantages of bio-fuel? What is the power output?1) Renewable
2) Leads to GHG, Expensive
Power output is medium - 30What are some advantages and disadvantages of solar? What is its power output?1) Renewable, no GHD, no solid or liquid waste
2) Expensive and inefficient, not consistent
Power output is low - 31What is the power output for wind?Power output is low
- 32What are some advantages and disadvantages of water electricity? What is its power output?1) Renewable, reliable, no GHG
2) Expensive, environmental damage, limited location available
Power output is high - 33What are some advantages and disadvantages of geo-thermal? What is its power output?1) Renewable, small emission of GHG
2) Limited location and expensive
Power output is medium - 34How do we save on energy consumption?1) Energy losses need to be reduced
2) % of useful energy obtained from a source needs to be increased - 35How are energy losses in the home reduced?1) Energy saving light bulbs
2) Switching off light switches and other appliances
3) Installing double/triple glazed windows - 36How can energy losses in national context be reduced?1) Increase use of public transport
2) Encourage car sharing and fewer journeys
3) Encourage recycling
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- GSCSE Science Flashcards on P3 Science revision flashcards, created by Jessica Brown on 16/05/2015.
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- Jessica Brown
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