# Energy and Effciency

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• Created by: Curlot
• Created on: 03-07-13 17:44
Energy Can't be .....
Created or destroyed
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Energy can be...
Transferred and usually stored
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Wasted energy becomes increasingly spread out and so...
Warms it's surroundings
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A light bulb transfroms electrical energy into...
Light energy
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But most energy is wasted beacuse...
The bulb becomes very hot
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A diagram that shows the relative proportions of energy transfer is called...
A Sankey Diagram
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The effiecincy of a device refers to the proportion of energy....
That is usefully transferred
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The greater the proportion of energy that is usefully transferred
the more efficient and cost effective a device is.
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Pay back time
can be calculated as £600/£60 per year=10 years
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Effiecincy values are normally expressed as
Either a percentage or a decimal
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Effiecincy can be calculated by using this equation.
Efficiency = ufeful energy or useful power out/ total energy x 100%
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## Other cards in this set

### Card 2

#### Front

Transferred and usually stored

Energy can be...

### Card 3

#### Front

Warms it's surroundings

Light energy

### Card 5

#### Front

The bulb becomes very hot