Question

Many domestic hair-dryers have no earth wire. Why?
1- The fan prevents the heating coil from becoming too hot
2- the current is small
3- The casing of the hair dryer is made of plastic material
4- the plug is installed with a fuse

Answer 1

Hint: Earth wire is used for safety purposes. While using any electrical appliance there are usually three wires which go into the plug switch. One is live wire for the incoming electrons and the other is neutral wire for the movement of electrons out of the appliance. The third is the earth wire and that is used to avoid any leakage of current.

Complete answer:
If the live wire accidentally touches the body of the appliance that we are using then it is quite possible that we may get an electric shock. So, in order to avoid that shock earth wire is used which neutralizes that current back into the earth. But the body of the hair dryer is all plastic and there is no metal on it. Since plastic is a poor conductor of electricity there are no chances of getting an electric shock and thus they have no earth wire. Thus, the casing of the hair dryer is made of plastic material and we can’t get a shock.

So, the correct answer is “Option C”.

Note:
Conductors conduct electricity while insulators do not. Plastic is a very bad conductor of heat and current and that is the cause why it is used for insulation of wires and making other such electrical appliances which are used in everyday lives. The third is the earth wire which is used in switching and all to avoid any leakage of current.