Alternating Current (AC) and Direct Current (DC) are two types of currents that are used for sending electricity in all parts of the world. Both currents have their special features with advantages and are used in different devices as well. While DC is unidirectional and flows in one direction only, AC rises and falls as it continually changes direction. However, they are similar in nature as both involve flow of electrons. But their similarity ends here as they are fundamentally different and their difference starts with the way two are produced and also the way they are transmitted and used.
Alternating Current
AC is the type of current that is supplied to provide electricity to homes and businesses. The reason why it is chosen over DC is because of its ease of production and transmission. In power plants whether they are coal based, wind turbines or hydro power, current is produced in rotating turbines which thus produces AC. A turbine, when rotating produces magnetic field that pushes and pulls electrons in the wire. This constant pushing and pulling produces a current that is constantly changing direction, and hence an alternating current.
Direct Current
DC is the type of current that is produced by a source that has no moving parts. Good examples of DC are solar panels and ordinary batteries. The chemical energy inside a battery pushes electrons in one direction only and thus the current that is produced is also unidirectional. One unique thing that you may not know is that most of the electronic devices such as TV’s and DVD’s have a built in AC/DC adapter as they operate on DC while the supply in homes is AC.
DC is more suitable for transportation over long distances despite it not being used by the consumers. It is converted back into AC before being sent to homes and businesses.
Electronic devices require a constant current which is not possible with AC as it is constantly reversing. However, there are devices like bulbs, fans, CFL etc. which can operate on both AC and DC as they only require flow of electrons and direction is immaterial to them. You may not notice but when a light bulb is on using AC, it constantly turns on and off as AC changes directions 50-60 times in a second. But since this changing is so fast, we cannot even notice if the bulb is going of and on. Devices like washing machines can work only on AC as its motor can spin on AC only. With automatic washing machines, it has become really complicated with motor running on AC while its screen and computer with DC with the help of a DC converter.
It is not possible to compare AC and Dc as both have their advantages as explained through use of devices in home. Both of them are required and without both many of the devices we rely so heavily upon will not operate.