P1.2 Flashcards
Cost =
Number of kilowatt hours x cost per unit
Cost
—————- =
Savings per year
Payback time (years)
Energy can’t be…
Created or destroyed
What do electricity costs depend on?
~ Amount of appliances used
~ Time appliances used for
What are the 3 types of potential energy?
~ Chemical
~ Elastic
~ Gravitational
What are the 7 types of energy?
Sound Heat Electrical Light Potential Nuclear Kinetic
What energy do devices such as lightbulbs, kettles and TVs take in?
Electrical
What energy does a TV produce?
~ Sound
~ Light
~ Heat
How does double glazing reduce heat loss?
There is a vacuum between the glass which stops heat loss through convection
Why is LED lighting efficient?
Produces the same amount of light brightness whilst using less electricity
What is a virtual image?
The rays of light seem to come from it but do not pass through it