Energy And Electricity Flashcards
What is energy needed for?
Keep our bodies working
Make machines work
Heat homes, schools and offices
Name all of the different forms of energy.
Sound Nuclear Solar/light Thermal/heat Kinetic Chemical potential Gravitational potential Elastic potential Electrical
Name the energies in action
Heat energy Light energy Sound energy Electrical energy Kinetic (movement) energy
What is chemical energy stored in?
Food
Fuels
Cells
What is gravitational potential energy stored in?
High up things
What is elastic energy stored in?
Stretched or squashed things
What is nuclear energy stored in?
Atoms
How is energy measured?
Joules (J)
Kilojoules (kJ)
There are 1000 joules in a Kilojoule
There are 1000000 (1 million) joules in a megajoule
Describe energy
Energy cannot be made or destroyed, but it can only be changed from one form to another. This is the law of conservation of energy.
What is needed for a voltage?
A circuit with a cell or power supply.
What does voltage do?
Pushes electrons around the circuit and gives them energy.
What happens to energy in a circuit?
The electrical energy is transferred to other components in the circuit, which convert into other forms of energy. For instance, a lightbulb transfers electrical energy into heat and light energy.
Electricity is supplied to homes and factories as ____________ _____________.
This travels along cables connected to the ______________ ________.
Mains electricity
National Grid.
In an average power station, what is burnt to release heat energy?
Fossil fuels
Describe the step by step process of generating electricity in power stations.
First fossil fuels are burnt. This releases beat energy and this is used to turn the water into steam.
The steam is forced through fans called turbines making them turn around.
The turbines turn generators. These are large magnets inside massive coils of wire. A moving magnet inside the coils of wire creates electricity and an electrical current.
The electricity flows through a transformer and into cables which flow into the National Grid.
What does the transformer do?
It changes the amount of voltage to 230 volts, the safe voltage for household appliances. This is called “step down”
What is nuclear fuel made from?
A radioactive metal called uranium.
Name one form of energy that does not come from the sun?
Nuclear energy.
Where else can electricity be generated from?
Renewable sources such as
Wind
Moving water
Why do we need renewable energy?
Because one day fossil fuels will run out and we will need to replace them.
What can be used for portable electricity and when do we need it?
Cells (batteries) are needed when we are not close to the mains.
What do cells store?
What happens when they run out of energy?
Chemical energy which can be changed into electrical energy.
Cells go flat when they run out of chemical energy. Some cells can be recharged.
Not all energy can be….
…turned into a form we want, therefore a lot of energy is wasted.
Give an example of useful and wasted energy in a car.
Useful- kinetic.
Wasted- heT and sound.
