# Electrical energy

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• Created by: Sam Evans
• Created on: 23-05-14 20:11
What is the useful energy transfer in an electric toaster?
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How may energy be wasted in an electric heater?
As light from the glowing filament
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How may energy be wasted in an electric kettle?
Heating the body of the kettle itself and sound
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How many kilowatts are equivalent to 30000 watts?
30kw
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Which is more powerful, a 2000w hairdryer or a 2.2 kw hairdryer?
2.2 kw
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What quantity is measured in kilojoules?
Energy is measured in kilojoules
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An electric light bulb transfers 6000J of energy in 1 minute. What is its power?
100w
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Why is the electrical energy supplied by the mains measured in kilowatt-hours?
The joule is too small to be useful in this situation
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## Other cards in this set

### Card 2

#### Front

How may energy be wasted in an electric heater?

#### Back

As light from the glowing filament

### Card 3

#### Front

How may energy be wasted in an electric kettle?

### Card 4

#### Front

How many kilowatts are equivalent to 30000 watts?

### Card 5

#### Front

Which is more powerful, a 2000w hairdryer or a 2.2 kw hairdryer?