Concept_3_Electricity
What can electricity do to you?
What can electricity do to you?
Electrical safety
The human body, though its muscles and nerves are controlled by electrical pulses, is not a good conductor of electricity. Neither is the air Lightning is a good example of what electrical charges can do if enough energy builds up: the discharge blasts its way through the air.
Normal, non-rechargeable batteries up to 4.5V can be used safely in the classroom, as long as the children do not attempt to eat them or throw them at each other (the chemicals are toxic). I have known children to complain of getting 'shocks' when working with circuits; but in every case, this was due to them catching their fingers with crocodile clips or ends of wire.
Rechargeable batteries
These can be very cost-effective when used in working models or toys where the circuit has been tested and is correct. When experimenting, children may accidentally 'short circuit' the battery by connecting a wire directly from one terminal to the other.This will allow the charge to flow very easily, leading to a build-up of heat; rechargeable batteries can discharge very quickly, given the opportunity.The heat will either manifest itself in the wire (it may melt the plastic covering) or in the battery (the chemicals may expand and squirt out). Whilst most rechargeable batteries have means to prevent this happening — you can't be too careful!
Mains electricity
As a general rule, children should not operate mains equipment, especially at the wall socket. Having said that, items of equipment such as computers and glue guns are quite frequently placed in the hands of children, following appropriate safety training. All electrical equipment must be checked for safety on a regular basis by a qualified technician, and classroom ring mains (the wall sockets) should be protected with earth-leakage breakers which will turn the electricity off as soon as it is detected leaking out of the system.There will be a reset button somewhere nearby, usually quite high up on a wall. Check for any problems before you attempt to reset; if in doubt, call for an electrician,
Children are very familiar with equipment that uses electricity, and are often allowed to operate it. In most cases this is quite safe, but familiarity can breed contempt for safety issues.They need to be made aware of the potential dangers of working with electricity, and how these hazards can be minimised.
Safety session
Use resources available from your local electricity company to highlight safety issues.The children can watch safety videos, circle hazards on posters and devise safety slogans.