Sometimes, when we visit a hairdresser’s shop for cutting or shaping our hair we find them using an appliance for drying hair. This is known as a hair dryer. Now, how does this hair dryer work?
We are aware of the fact that the electric heater, electric bulb, immersion heater, etc. are domestic appliances, which work on the heating effects of electric currents. Hair dryer also works on the same principle.
A hair dryer consists of a cover usually made of plastic, and shaped like a pistol. Inside this plastic cover, electric current is passed though a coil of nichrome wire and it gets heated up duet o the high resistance offered by the coil. At the back of this coil, a small electric fan is fitted.
The hair dryer has two switches; one operates the fan the other allows the current to pass through the nichrome coil. When the first switch is put on, the electric fan starts running and the cold air comes out form the dryer, and when the second switch is put on, the coil gets heated up and as a result, the air now passes over the heated coil and gets heated. The hot air blows moisture-laden air away from the hair, thus drying them.
This apparatus is not only used to dry hair but also for drying in the research laboratories in a number of experiments where drying process is necessary.