Difference between revisions of "Energy Efficiency"
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===About Efficiency=== | ===About Efficiency=== | ||
: '''Energy efficiency''' is a [[measure]] of how effectively [[energy]] is [[Energy Transfer|transferred]] from one [[Energy Store|energy store]] into an intended [[Energy Store|energy store]]. | : '''Energy efficiency''' is a [[measure]] of how effectively [[energy]] is [[Energy Transfer|transferred]] from one [[Energy Store|energy store]] into an intended [[Energy Store|energy store]]. | ||
| − | : '''Efficiency''' may be written as a [[percentage]] or as a | + | : '''Efficiency''' may be written as a [[percentage]] or as a decimal. |
| − | : '''Efficiency''' as a [[percentage]] can never be greater than 100% and as a | + | : '''Efficiency''' as a [[percentage]] can never be greater than 100% and as a decimal can never be greater than 1 because you can never get more [[energy]] out than you put in due to [[Conservation of Energy]]. |
===Equation=== | ===Equation=== | ||
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<math>Efficiency = \frac{E_{Useful}}{E_{Total}}</math> | <math>Efficiency = \frac{E_{Useful}}{E_{Total}}</math> | ||
| − | Where | + | Where: |
E<sub>Useful</sub> = The [[Useful Energy]] [[Energy Transfer|transferred]] to a device's intended purpose. | E<sub>Useful</sub> = The [[Useful Energy]] [[Energy Transfer|transferred]] to a device's intended purpose. | ||
E<sub>Total</sub> = The [[Total Energy]] [[Energy Transfer|transferred]] to a [[system]]. | E<sub>Total</sub> = The [[Total Energy]] [[Energy Transfer|transferred]] to a [[system]]. | ||
| + | |||
| + | ===References=== | ||
| + | ====AQA==== | ||
| + | |||
| + | :[https://www.amazon.co.uk/gp/product/019835939X/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=019835939X&linkCode=as2&tag=nrjc-21&linkId=57e96876985fc39b1a3d8a3e3dc238b6 ''Energy efficiency, pages 16-19, 21, GCSE Physics; Third Edition, Oxford University Press, AQA ''] | ||
| + | |||
| + | ====Edexcel==== | ||
| + | |||
| + | :[https://www.amazon.co.uk/gp/product/1292120193/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120193&linkCode=as2&tag=nrjc-21&linkId=572df39392fb4200db8391d98ae6314e ''Energy efficiency, pages 318-319, GCSE Combined Science, Pearson Edexcel ''] | ||
| + | :[https://www.amazon.co.uk/gp/product/1292120223/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120223&linkCode=as2&tag=nrjc-21&linkId=068ecf40278c32406a7f1c6e66751417 ''Energy efficiency, pages 36-37, GCSE Physics, Pearson Edexcel ''] | ||
Latest revision as of 13:48, 19 November 2019
Contents
Key Stage 4
Meaning
Energy efficiency is a ratio of Useful Energy transferred to total energy put into a system.
About Efficiency
- Energy efficiency is a measure of how effectively energy is transferred from one energy store into an intended energy store.
- Efficiency may be written as a percentage or as a decimal.
- Efficiency as a percentage can never be greater than 100% and as a decimal can never be greater than 1 because you can never get more energy out than you put in due to Conservation of Energy.
Equation
Efficiency = (Useful Energy Out)/(Total Energy In)
\(Efficiency = \frac{E_{Useful}}{E_{Total}}\)
Where:
EUseful = The Useful Energy transferred to a device's intended purpose.
ETotal = The Total Energy transferred to a system.