Electrical Energy Flashcards
What are the forms which energy can change to
Chemical energy Nuclear energy Kinetic energy Gravitation potential energy Elastic potential energy Light energy Sound energy Heat energy
What can energy change to
It can change from one forms to another
What can’t energy do
It cannot be creat or destroy
Give and example to explain how energy cannot be created or destroyed and what is it called
When an object falls, it’s gravitational portent ion decreases and it’s kinetic energy increases
It is called conservation of energy
What is useful energy
It is energy in the form which we need it
What does a sankey diagram show
It represents the energy transfers in a device
What do both useful and wasted energy end up being
It ends up being a transferred into the surroundings which become warmer
What is energy measured in
Joules
Which are the two formulas used to calculate efficiency
Efficiency%=(useful energy transferred/total energy supplied)*100
Efficiency%=(useful power output/total power input)*100
What can no machine be more efficient than
100%
How can efficiency be improved
By reducing friction, reducing electrical resistance ect.
What is power
It is the rate of transfer energy
What is power measured in
Watts (w)
What does 1kWh (kiloWatt) = to
1000wattes
What is the kilowatt hour
It is the energy supplied to a 1kW devices in 1hour
