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Y9SciPhyTopic5
Year 9 Science Physics Topic 5 Generation and Transmission of Electricity
Question | Answer |
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Electricity | a flow of charged particles that can be used to transfer energy. |
Current | a flow of charge. |
Voltage | a measure of the amount of energy transferred by a current. |
Renewable energy resources | resources that will not run out, such as solar or wind power. |
Solar cells | a device that converts light energy into electrical energy. |
Solar energy | energy from the sun. |
Hydroelectricity | electricity generated using the transfer of gravitational potential energy to kinetic energy by falling water. |
Wind turbines | a kind of windmill that generates electricity when moving air turns a set of turbine blades. |
Geothermal energy | energy transferred from hot rocks deep beneath the earth’s surface. |
Tidal power | generating electricity using the movement of the tides. |
Wave power | generating electricity using the movement of water waves. |
Non-renewable resources | resources that cannot be replaced once they have been used. Non-renewable resources will eventually run out. |
Fossil fuels | non-renewable fuels such as coal, oil and natural gas that have formed over millions of years from dead plants and animals. |
Nuclear power | generating electricity using energy stored in nuclear fuels. |
Climate change | changes to the earth’s climate, or changes in weather patterns on a global scale. |
Acid rain | rain that is more acidic than normal, due to sulphur dioxides and nitrogen dioxides dissolved in it. |
Decommission | to dismantle safely. |
Magnetic field | the area around a magnet where it can affect magnetic materials or induce a current. |
Electromagnetic induction | process that creates a current in a wire when the wire is moved relative to a magnetic field, or when the magnetic field around it changes. |
Induced current | the current that flows in a wire that is moving relative to a magnetic field. |
Dynamo | a small machine that generates electricity using a spinning magnet. |
Direct current (DC) | a current that flows in one direction only, such as the current produced by a cell. |
Generator | a machine that makes electricity when it turns. |
Slip rings | rings connected to the coil of a generator to make an electrical connection to a circuit. They allow the coil to spin without the wires becoming twisted. |
Carbon brushes | blocks of carbon connected to a circuit. They press against slip rings to make an electrical connection between the circuit and the spinning coil in the generator. |
Alternating current (AC) | current whose direction changes many times each second. |
Electromagnets | a magnet made using a coil of wire with electricity flowing through it. |
National Grid | the system of wires and transformers that distributes electricity around the country. |
Efficiency | the proportion of input energy that is transferred to a useful form. |
Transformer | a device consisting of two coils of wire on an iron core which can change the voltage of an alternating electricity supply. |
Step-up transformer | a transformer that increases the voltage. |
Step-down transformer | a transformer that decreases the voltage. |
Primary coil | the coil on a transformer to which the electricity supply is connected. |
Secondary coil | the coil on a transformer where the changed voltage is obtained. |
Joule (J) | the unit if energy. |
Power | how quickly something transfers energy. |
Watt (W) | the unit for measuring power. 1 watt = 1 joule of energy transferred every second. |
Kilowatts (kW) | |
Kilowatt-hour (kWh) | |
Unit | the unit of measurement for the amount of energy transferred. A Unit is the same as a kilowatt-hour. |
Payback time | the time it takes to get back in savings the money spent on making the change. |
Cost-efficient | something that saves a lot of money compared to how much it costs. |