EXAM Energy and electricity Flashcards
What is an electrochemical cell?
A device that’s stored chemical energy into electrical energy. A battery is made up of one or more cells.
In what direction do electrons flow in an electrical circuit?
From the negative to the positive
What does it mean if a batty becomes flat or dead?
All the electrical energy has been drained from the battery.
Why should flat batteries be recycled and not thrown away?
Harmful chemicals from the battery can leak and pollute soil and water and harm people’s health. They can also explode in a fire.
Name the 4 important parts that make up the electrical circuit in a torch.
Battery, switch, light bulb and connecting wires.
During electricity generation using fossil fuels the gases nitrogen dioxide, sulphur dioxide and carbon dioxide are created. Which of these are greenhouse gases and which create air pollution?
Carbon dioxide is a greenhouse gas.
Sulphur dioxide and nitrogen dioxide are air pollutants (and cause acid rain)
A material that allows electricity to pass through it is called a …
Conductor
A martial that prevents electricity from passing through it is called an …
Insulator
What is a series circuit?
A circuit in which the current can only follow through one path.
What is a parallel circuit?
The current splits at some point in the circuit to follow more than one path.
Give the colors of the three different wires connected to a three pin plug.
Earth- green and yellow
Live - brown
Neutral - blue
Explain briefly how electricity is generated at Koeberg (nuclear power station)
The nuclear fuel (uranium) reacts and produces heat which is used to create steam. The steam drives a turbine which causes a generator to produce electricity.
What is the role of a sub-station in electricity distribution.
The substation steps up the voltage before the electricity is sent through the transmission lines. The voltage is then stepped down before it comes into our houses.
What are the disadvantages of a coal fired power station?
Mining coal can damage the environment and people’s health. Burning coal creates air pollution and releases greenhouse gases.
