Topic 2 Power Of Electrical Appliances Flashcards
Energy transferred =
Power x time
Why does moving charge transfer energy (do work)
The charge does work against the resistance of the circuit
How do kettles transfer energy
Electrically from the mains ac supply to the thermal energy store of the heating element in the kettle
Energy transferred into hand held fan
Transferred electrically from the battery of a handheld fan to the kinetic energy store of the fans motor
The higher the current what happens to the energy transferred
More energy is transferred to the thermal energy gores of the components
What does the total energy transferred depend on
How long the appliance is left on for and it’s power
What is the power
The amount of energy transferred per second
What is a power rating
The maximum safe power an appliance can operate at
It is normally their maximum operating power
What does the power rating tell you
The maximum amount of energy transferred between stores per second when the appliance is in use
How do power ratings help people chose between models
Lower the power rating the less electricity an appliance uses in a given time so it is cheaper to run
Why might a high power rating not be the best
May be more powerful but less efficient meaning that it still might only transfer the same amount of energy to useful stores
