An example of alternating current is electricity supplied to homes and businesses through the power grid. In most countries, the standard household power supply is alternating voltage with a frequency of 50 or 60 Hertz, depending on region. For example, in the United States the standard is 120 V AC at 60 Hz, while in Europe it is usually 230 V AC at 50 Hz. This AC power is used to power various appliances and lighting fixtures in buildings residential and commercial.
Types of AC are mainly classified based on their waveform and frequency.
The most common type is sinusoidal alternating current, which has a smooth, continuous waveform and is used for most power distribution systems. There is also square wave alternating current and triangular wave alternating current, which are less common and used in specialized applications such as in certain types of signal processing or electronic devices. Sinusoidal alternating current is preferred for power transmission due to its efficiency and ease of transformation.
Devices using alternating current include a wide range of household and industrial appliances.
Common household appliances include refrigerators, washing machines, air conditioners and televisions. Industrial equipment such as motors, transformers and compressors also run on alternating current. Alternating current is preferred for these devices due to its efficient transmission and ability to be easily transformed into different voltage levels.
To determine whether a current is direct or alternating, you can use a multimeter or oscilloscope.
A multimeter configured to measure AC voltage will display an AC current value, while a multimeter configured to measure DC voltage will display a constant value if the current is DC. An oscilloscope can visually display the current waveform; a sine waveform indicates alternating current, while a solid line or straight continuous waveform indicates direct current.
We use AC power in the home primarily because it is more efficient in transporting and distributing electricity.
Alternating current can be easily transformed into different voltage levels using transformers, allowing high voltage transmission over long distances with minimal energy loss. Once at your destination, the voltage can be reduced to safer, usable levels for household appliances. This efficiency and adaptability makes AC the preferred choice for residential electrical systems.