314536
| Question | Answer |
| What is meant be 'energy is conserved'? | Energy can neither be created nor destroyed. |
| What is a primary energy source, with an example? | One that occurs naturally - coal, oil, wind, gas, wood, waves and sunlight. |
| What is a secondary energy source, with an example? | An energy source generated using a primary source - electricity, hot water used in heating systems, steam. |
| What is biofuel, with an example? | A fuel that comes from biomass, or organic material. These could be wood, straw, sewage or sugar. |
| What is sustainability? | Using resources and the environment to meet the needs of people today without damaging the Earth or reducing resources for people in the future. |
| What is power? | The rate at which energy is used. |
| What is 1 watt? | 1 watt (W) uses 1 joule (J) every second. |
| What is a kilowatt-hour and how many joules does it stand for? | 1 kilowatt (1000 W) X 1 hour (3,600 s) = 1 kWh (3,600,000 J) |
| What is the unit for energy used? | The kilowatt-hour. |
| How is cost of energy worked out? | Cost = kilowatt-hours X pence per kilowatt-hour |
| How is power calculated? | power (W) = voltage (V) X current (A) |
| What is the mains voltage in the UK? | 230 V |
| Why does the energy bill not account for all the energy our lives use? Include an example. | There's other stuff - the energy cost of things like packaging, food, driving, armed forces, government and computer servers. |
| How is an efficiency percentage calculated? | (energy usefully transferred) divided by (energy supplied to the appliance) X 100 |
| Describe a Sankey diagram. | Branching arrows show how much energy is used and how much is lost as heat etc. The width of the arrows always adds up the width of the Sankey. |
| What happens when a bar magnet is moved into or out of a coil? | A current is generated or 'induced' in the coil. |
| What is this magnet and coil thing called? | electromagnetic induction |
| What is a.c.? | Alternating current is generated by electromagnetic induction. |
| How does a thermal power station work? | Fuel is burnt to heat water, making steam that turns a turbine, turning a magnet in a generator, producing electricity. |
| Why aren't thermal power stations efficient? | Energy is wasted, carried away as heat in steam and exhaust gases. |
| What are the four advantages of nuclear power? | No CO2 is produced. Much less uranium is needed for the same energy output. There hundreds of years worth of uranium fuels left. Energy is cheaper! |
| What are the 5 disadvantages of nuclear power? | The waste is dangerous and has to be stored. It's a security threat. It's non-renewable. Uranium is sourced from unstable countries. The reactors have to be dismantled - this is expensive. |
Want to create your own Flashcards for free with GoConqr? Learn more.