electrical appliances Flashcards
useful and wasted energy from electric heater
useful- heat
wasted- light
useful and wasted energy from toaster
useful- heating bread
waste- energy heating the toaster
useful and wasted energy from hairdryer
useful- kinetic and hear
waste- sound, heating hairdryer
what affects the rate of how fast an appliance transfers energy
the more powerful an appliance the faster it transfers energy
how to calculate power
power= energy/ time
what is 1 Watt equal to in Joules
1J/s (one joule per second)
how to work out power effientcy
same as energy
what does the energy supplies to an appliance depend on
- how long it is used for
2. the power supplies to it
equation for how much energy is supplied to something
energy= power X time
what does the electricity meter in your home measure
how much electrical energy your family uses (kWh)
equation to work out total cost
total cost= number of kWh used X cost per kWh
what does cost effective mean
how much something gives value for money
what to consider when considering cost effectiveness
- capital costs- buying/ installing
- running costs- fuel/ maintenance
- environmental costs- tax/ disposal
- other- interest on loans
useful and wasted energy from lightbulb
useful- light
wasted- heat
how easily can electrical appliances transfer electrical energy into useful energy
electrical appliances can transfer electrical energy into useful energy at the flick of a switch
what do we use everyday appliances for
heating lighting creating doubt creating visual images making objects move
how much energy should an electrical appliance waste
an electrical appliance is designed for a particular purpose
and should Waste as little energy as possible
what is power
the rate of transfer of energy
what is kWh a unit of
a unit of energy
