GCSE Physics: Electrical Safety
Although electricity is very useful to us it can also be very dangerous. Electrical faults can cause fires which damage property and sometimes result in injury or death. You can also give yourself a shock from the amins, and electric shocks do occasionally kill people. The purpose of this usint is to teach you how to keep your home safe.Fuses
The purpose of a fuse is to prevent fire. A fuse can also protect equipment. If you use a device such as a lawnmower and you cut through the wire which is very likely to cause a fire. The fuse is put into the live wire which melts if the current gets above a certain level the wire inside breaks the circuit. However, fuses are slow to act, not immediate and do not protect against electrical shock. Circuit breakers orRCD’s theor open a switch which can easily be reset.
Choosing a fuse
A fuse is fitted to a plug to prevent fires. It does not provent electrocution. A fuse will melt and eventully break if the current gets too high. The size of a fuse fitted depends on the power rating of the appliance.
Power = Current * Voltage The higher the power ratng, the more current the device takes, sice the voltage is constant (240V).
| Appliance | Power | Voltage | Current | Fuse |
| Kettle | 2400 | 240 | 10 | 13A |
| Video | 30 | 240 | 0.125 | 0.5A |
| Heater | 960 | 240 | 4 | 13A |
| Light Bulb | 100 | 240 | 0.416 | 1A |
| Car Headlamp | 30 | 12 | 2.5 | 5A |
| Electric Circuit | 0.2 | 5 | 0.04 | 0.5A |