Concept_2_Electricity
How do we use Electricity?
How do we use Electricity?
This should be considered on two levels. Firstly, what things use electricity as their main power source? Secondly, what form of electricity do they use?
Most households have a vast range of electrical equipment that they have come to rely on, from a tumble-dryer and a TV to alarm clocks and light bulbs.The identification of things that use electricity can be based on looking for cables coming out of the back that attach to wall sockets. But you can't always see the cables; and even when you can, it doesn't mean that electricity is the main power source — electrical switching often controls gas cookers and central heating systems.
Many items of equipment have the option of using either mains or battery. For example, a radio may be designed to run on batteries and also contain a device for transforming mains AC to DC at the correct voltage. Battery-powered toys use electricity to produce movement, light or sound.
Children will be aware of electricity as the most commonly used energy source; but they need some understanding of its uses to be able to use it safely. see concept 3
Current — the rate of flow of electricity, measured in amps (A). Power — how much energy is used in a given time, measured in joules per second or watts (W).
Voltage — the difference in potential between two parts of a circuit, 'pushing' the current. Voltage is measured in volts (V).
Commercial imitations of non-electrical objects, such as candleshaped light bulbs or 'coal-effect' fires, may confuse children who have never seen the real thing and hence assume that the latter requires electricity!
There can be some confusion about rechargeable electrical items such as hand mixers or remote-controlled toys. Children may think that the electricity is coming directly from the mains. In reality, mains electricity is used to recharge the special batteries stored in the device.
Mains and battery (sorting)
The children can use an old catalogue of electrical goods to make a collage of two sets: mains-powered and battery-powered equipment.They could show an intersection (objects that use both) if appropriate. distribution box.
Alternatives (matching)
The children can return to the catalogue, cutting out and mounting five or so examples of equipment which make different uses of electricity (such as a battery shaver, digital alarm clock, hairdryer, food mixer or a fan heater), then find non-electrical alternatives (a wet razor, clockwork alarm clock, towel, hand whisk or a gas fire).