What is Alternating Current?
https://www.allaboutcircuits.com/textbook/alternating-current/chpt-1/what-is-alternating-current-ac/
While direct current is known as electricity that takes a constant direction in a circuit, alternating current is known as electricity that alternates its polarity over time time like the graph of sine, thus making it constantly change the path it takes in a circuit. Alternating current is generally used in the distribution of electrical energy due to its advantage that a transformer can be used to increase or decrease its voltage as needed. Because of this, electrical energy can be transmitted at high voltages with very little energy is turned into heat due to the lack of resistance from wires, then transformed into a lower power safer form for use with a transformer. Today, alternating current is used to transport information (ex. cable and telephone signals).
When it comes to industry, alternating current generally doesn't have more practical advantages than direct current does. However, alternating current is used in most of the world in cases which involve electric motors, generators, and systems of power distribution. To understand why, one must know a bit more about the science of how alternating current works.
According to Faraday's law of electromagnetic induction, an alternator can be created when a magnetic field is rotated around wires that remain stationary. While it is rotating, the current in the wires alternates depending on the position of the magnetic shaft. This is known as an AC operator, or an alternator.
Direct current also works on the principle of Faraday's law of electromagnetic induction, but the setup is much more complicated. In direct current generators, a coiled wired is connected to a shaft and carbon brushes must connect to the copper strips on the rotating shaft. The reason for this is because the coil's output polarity is constantly changing so it must be switched in order for the external circuit to see a constant polarity. Afterwards, the DC generator will produce two voltage pulses for every time the magnetic shaft makes a revolution. This becomes an issue because you want constant voltage rather than voltage to be in "pulses." In order to make the current constant, multiple coils with contact with carbon brushes need to be set up. This creates an even more complicated issue because when too many coils and brushes are set up, heat becomes produced much more easily which can create issues for the entire system. The coils and brushes in contact are also at risk of occasionally "sparking" which can be a fire hazard. Because of this more complicated setup and the issues associated with the setup, alternating current is often used in industry due to the low cost and better reliability.
Alternating current also has other benefits other than its low cost and less complicated setup. In power distribution, electrical power must be transported to many different areas over long distances. To do this effectively, it is most efficient to transport it with high voltage and low currents, then have it "transformed" to a lower voltage and higher current when delivered to homes and businesses. The use of transformers has made this possible. However, transformers will only work with AC and not DC. As a result, we see AC much more common in power transportation applications.
When it comes to industry, alternating current generally doesn't have more practical advantages than direct current does. However, alternating current is used in most of the world in cases which involve electric motors, generators, and systems of power distribution. To understand why, one must know a bit more about the science of how alternating current works.
According to Faraday's law of electromagnetic induction, an alternator can be created when a magnetic field is rotated around wires that remain stationary. While it is rotating, the current in the wires alternates depending on the position of the magnetic shaft. This is known as an AC operator, or an alternator.
Direct current also works on the principle of Faraday's law of electromagnetic induction, but the setup is much more complicated. In direct current generators, a coiled wired is connected to a shaft and carbon brushes must connect to the copper strips on the rotating shaft. The reason for this is because the coil's output polarity is constantly changing so it must be switched in order for the external circuit to see a constant polarity. Afterwards, the DC generator will produce two voltage pulses for every time the magnetic shaft makes a revolution. This becomes an issue because you want constant voltage rather than voltage to be in "pulses." In order to make the current constant, multiple coils with contact with carbon brushes need to be set up. This creates an even more complicated issue because when too many coils and brushes are set up, heat becomes produced much more easily which can create issues for the entire system. The coils and brushes in contact are also at risk of occasionally "sparking" which can be a fire hazard. Because of this more complicated setup and the issues associated with the setup, alternating current is often used in industry due to the low cost and better reliability.
Alternating current also has other benefits other than its low cost and less complicated setup. In power distribution, electrical power must be transported to many different areas over long distances. To do this effectively, it is most efficient to transport it with high voltage and low currents, then have it "transformed" to a lower voltage and higher current when delivered to homes and businesses. The use of transformers has made this possible. However, transformers will only work with AC and not DC. As a result, we see AC much more common in power transportation applications.