# GCSE Physics OCR P3 Sustainable Energy

version from 2016-05-24 18:10

## Section

Question Answer
What are some examples of primary sources?Fossil fuels such as coal and gas, nuclear fuel such as uranium, biofuels from plants and animals, wind waves and sunlight
What can primary energy sources transfer their energy to?Secondary energy sources such as electricity
What is most our electricity made from?Burning fossil fuels which are non renewabld
What is power?The amount of energy transferred in one second
What is the equation for power?Energy transferred (in J)= power (in W) x time (in s)
What is a joule?A very small amount of energy
What is a kilowatt- hour?The energy transferred by a power of 1 kW in an hour
What is the equation for a kWh transferring energy?Energy transferred (in kWh)= Power (in kW) x time (in hours)
What is a current?The flow of electricity in a circuit
What is the current measured in?Amperes
How does an electric an appliance transfer energy?From the power supply
What is a rating?The power of an electric device is the rate at transfers energy from the power supply
What does a current in a component do?Transfers electrical energy into other useful forms
What does a current in the connecting wires do?Wastefully transfers electrical energy to heat
How can information about energy use be displayed?Pie chart,bar chart, line graph
What do sankey diagrams show? The energy transfers in a component- the sum of the energy transfers out of a component equals the input energy
What does the efficiency of a component tell you?The proportion of electricity that it transfers into a useful form
How can you as a person use less electricity?Using high efficiency a rated appliances
How can a nation use less energy?Building more efficient power stations, living in houses with better insulation, more efficient cars
How can impact on environment be reduced?Recycling resources, generating electricity from renewable sources of energy
What does moving a magnet near a circuit cause?An electric current to flow in the circuit only when the magnetic field is changing (magnet is moving)
What do power stations use a magnet for?To produce mains electricity by generators
What does a generator contain?An electromagnet near a coil of wire- there is a voltage across a the coil when it spins
What do power stations use primary fuels for?To boil water into steam
what happens after power stations boil water into steam?Steam passes through turbine making its shaft spin round- turbine shaft spins the magnet inside the genetator
What is required when increasing the current drawn from the coil?An increase in rate of transfer of energy from primary fuel
What do thermal power stations use to spin the turbine from high pressure steam?Coal, oil, gas and nuclear power
What do hydroelectric power stations use to spin a turbine?A jet of high pressure water at the base of a dam
What do wind driven power stations use to spin a turbine?Convection currents in the atmosphere
How do nuclear power stations make high pressure steam?Putting fuel rods close to each other in reactor so they heat up, taking away heat pressure water circling around the rods, using the high pressure water to boil low pressure water in a boiler
Why is waste from nuclear power stations a serious health risk?It is radioactive
How does nuclear waste affect body cells?It emits ionising radiation
When is an object irradiated?When it is placed in the path of the radiation
When is an object contaminated?When it gets mixed up with radioactive material
Why is contamination a more serious hazard than irradiation? Can result in longer exposure to radiation, difficult to remove radioactive material, difficult to stop radioactive material spreading
Why do we often overestimate the risk from ionising radiation?cannot be seen or felt, effects take a long time to develop, people worry about unfamiliar technology
What renewable sources can spin turbines to make electricity?hydroelectric schemes, wind turbines, wave technology
What are advantages of hydroelectric schemes?provide large amount of electricity, can be turned on and off quickly, can pump water back behind the dam to store energy
What are disadvantages of hydroelectric schemes?flood large areas of land, rotting plants in the water produce methane gas, cost a lot to build
What are advantages of wind turbines?they are not expensive to make and need very little maintenance
What are disadvantages of wind turbines?they need to be put in windy places, can only generate electricity when there is enough wind
What is the national grid?a network of cables which carries electricity throughout the UK
Why do power cables warm up?they wastefully transfer electrical current to thermal energy
What does increasing the voltage of a power cable do?reduces the current
What is the efficiency of electricity generation?the proportion of the energy in the original fuel that is delivered to customers as electricity
What are energy sources that can produce large amounts of electricity?fossil fuels, nuclear power, hydroelectricity, biofuels
What are the energy sources that rely on the right sort of weather?wind, waves, solar
What are energy sources that do not produce greenhouse gases?Nuclear power, wind, waves, solar, geothermal
When choosing an energy source what should you consider?impact on environment, reliability, cost, how much waste it produces, cost of building and running the power station, effiency of the transfer of energy to electricity
Why is global demand for energy likely to rise in future?there will be more people, many of them want the high energy lifestyle of industrialised countries
What does a secure energy supply in the future require us to do?generate enough electricity to avoid power cuts, have constant access to energy sources, use efficient power stations, use more renewable energy sources