Electricity Continued Flashcards
What are fossil fuels?
The remains of dead plants and animals that store energy from the sun from millions of years ago
What are three types of fossil fuels?
Coal
Oil
Natural gas
Where does the energy in fossil fuels come from?
The sun
Explain how coal or fossil fuels are formed.
Millions of years ago, the Sun gave its energy to plants and animals. When they died, pressure from above and heat from the Earth over millions of years turned these dead plants and animals into black coal, oil or natural gas.
What is a non-renewable resource?
Resources that cannot be replaced when they are used up
Is coal a renewable or non-renewable resource? Why?
Non-renewable. It takes millions of years to form
Where was coal usually formed?
In low-lying wetland areas
Plans died and formed into layers of rotting material. Over time, pressure from above packed these layer together to form _______.
Peat
When _______ and ________ collected on these layers they were pressed together even tighter and made a soft brown layer called ________.
Sand
Water
Lignite
_________ ________ are things from our planet that will eventually run out.
Non-renewable resources
Are all fossil fuels non-renewable resources?
Yup:)
What is a power station?
A place where electricity is generated
What is a turbine?
The rotating blades of a machine
What is a generator?
A machine that produces electricity
What is the step by step process from coal to kitchen light?
- Coal from storage area to boiler
- Burns, heats water in boiler
- Hot water into steam
- Steam turns turbine
- The moving turbine of the generator produces electricity
- Travels along power lines over long distances
- Transformers at sub-stations reduce energy carried by electricity before it enters our homes
- People use electricity
What does Infrastructure mean?
The structures and other things that are needed to make sure something works properly
Why is generating and distributing electricity costly?
Because of the infrastructure that is required
What is wattage?
The amount of electrical power an appliance requires to work
Why do we pay for electricity?
It costs hundreds of billions of rands to build coal-burning fire stations. It also costs billions to keep all the structures and equipment working properly. For these reasons, electricity is very costly. When we pay for electricity, we are paying for the amount of energy our electrical appliances use
Why is a wattage rating helpful
It gives us an idea of how much electricity the appliance will use
Power is measured in units called ______. It is shortened to __.
Watts
W
Which requires more watts? Kettles or an average radio?
Kettles
Why is it bad to burn coal?
Waste products from burning coal pollute the air. This means they make the air dangerously dirty and can cause illness such as bronchitis and asthma
What usually uses most of a household’s electricity?
Hot water geysers
What are the benefits of a solar water heater and how does it work?
Using solar water heaters can help us to save electricity. Solar water heaters use the energy from the sun to heat water
What does it mean to not be energy efficient?
To waste a lot of energy
What are the benefits of energy saving light bulbs?
They use up to 75% less power than ordinary bulbs and last up to nine times longer
What is an illegal connection?
A connection of electricity wires that is not made by a qualified electrician or does not meet the standard of the electricity laws
Name 2 types of illegal connections.
Sometimes people run their own cables from the homes of others, making their own connections.
People connect wires to electricity poles to steal electricity because they do not want to pay for it
What is the main problem with illegal connections?
They are unsafe
What are renewable resources?
Resources that will not run out
List 3 renewable resources.
Energy from the Sun, wind and moving water
Give 2 examples of using wind power.
Wind pumps
Wind turbines
How does a wind pump work?
When the wind turns the windmill, water is pumped up from underground and stored in a dam
How does a wind turbine work?
It has a wheel with blades that turn in the wind. The wheel is on a very high tower. There is a box behind the wheel with a generator inside. When the blades turn, the generator makes electricity.
Where should you place a wind farm?
Where there is lots of wind
How can you use water power?
Moving water has energy. Some machines use the energy in moving water to do things like grind grain
What happens at hydro-electric power stations?
The energy in falling water is changed into electrical energy. The water comes from big dams across rivers and flows down large tubes to turn the turbines in the electrical generators
Photovoltaic solar panels have photovoltaic cells. What are photovoltaic cells?
Devices that convert sunlight into electricity. Photovoltaic cells can also be used in small circuits to power light bulbs, small motors or other small devices
