Power of Electrical Appliances Flashcards
What are electrical appliances designed for?
To transfer energy to components in the circuit when a current flows.
Can you give a example of electrical appliances and what they transfer?
A kettle-they transfer energy electrically from the mains ac supply to the thermal energy store of the heating element inside the kettle.
What does it mean if the current gets higher in a electrical appliance?
It means more energy is transferred to the thermal energy stores of the components and then the surroundings.
What is the total energy transferred by an appliance dependent on?
How long the appliance is on for and its power.
What is the power of an appliance?
The energy that it transfers per second.So more energy it transfers in a given time,the higher its power.
How do you calculate the energy the energy transferred(J)?
Power(W)*Time(s)
What are appliances often given?
A power rating
What are power ratings labelled as and why?
Maximum operating power because they are labelled with the maximum safe power that they can operate at.
What does the power rating tell you?
The maximum amount of energy transferred between stores per second when the appliance is in use.
Why do power ratings help customers?
They help to make a choice between models.
What does it mean if the power rating is lower?
The less electricity an appliance uses in a given a time and so the cheaper it runs.
Why doesn’t levels of power in an appliance mean anything?
A higher power doesn’t mean it transfers more energy usefully.
An appliance may be more powerful than another,but less efficient,meaning it might still only transfer the same amount of energy(or even less)to useful stores.
