Alternating Current (AC)

Definition

Alternating current (AC) is an electric current that periodically reverses direction, allowing for more efficient transmission of electricity over long distances compared to direct current (DC). This technology emerged as a crucial innovation in the late 19th century, significantly impacting power generation and distribution systems, facilitating the electrification of homes and industries, and enabling advancements in various electrical appliances and machinery.

5 Must Know Facts For Your Next Test

1. AC allows electricity to be transmitted over longer distances without significant losses, making it ideal for powering cities and rural areas.
2. The frequency of AC can vary, with standard frequencies being 60 Hz in North America and 50 Hz in many other parts of the world.
3. The development of AC power systems was primarily driven by innovators like Nikola Tesla and George Westinghouse, who advocated for its advantages over DC.
4. Alternating current enables the use of transformers, which can increase or decrease voltage levels efficiently, enhancing the safety and efficiency of power distribution.
5. AC is the standard form of electricity supplied to homes and businesses today, powering everything from lights to large industrial machines.

Review Questions

• How does alternating current improve the efficiency of electricity transmission compared to direct current?
  • Alternating current improves the efficiency of electricity transmission primarily because it can be easily transformed to higher voltages using transformers. Higher voltage transmission reduces energy losses due to resistance in the wires over long distances. In contrast, direct current would require thicker wires or more frequent boosting stations to maintain voltage levels, making it less practical for widespread distribution.
• Discuss the role of key figures like Nikola Tesla in the development and promotion of alternating current systems during the late 19th century.
  • Nikola Tesla played a pivotal role in the development of alternating current systems by inventing key technologies such as the AC induction motor and transformer. His innovations demonstrated the practicality and efficiency of AC for power generation and transmission. Alongside George Westinghouse, Tesla helped popularize AC systems over direct current during the 'War of Currents,' ultimately leading to widespread adoption that transformed electricity use across industries and homes.
• Evaluate the impact of alternating current on industrialization and urbanization in America during the late 19th century.
  • The advent of alternating current significantly accelerated industrialization and urbanization in America by enabling reliable and efficient power distribution across vast regions. As cities became electrified, industries could operate machinery at unprecedented scales, boosting productivity and economic growth. This electrification facilitated new innovations, improved living standards, and attracted populations to urban areas for job opportunities, marking a transformative period in American history as society shifted toward modern electrified living.

Related terms

Direct Current (DC): Direct current (DC) is an electric current that flows consistently in one direction, often used in batteries and low-voltage applications.

Transformers: Transformers are electrical devices that transfer electrical energy between two or more circuits through electromagnetic induction, allowing for voltage conversion in AC systems.

Electromagnetic Induction: Electromagnetic induction is the process by which a changing magnetic field creates an electric current, forming the basis for AC generators and transformers.