What is the standard frequency of AC in the United States?

What is the standard frequency of AC in the United States?

• A. 50 Hz
• B. 60 Hz
• C. 70 Hz
• D. 100 Hz

Answer: (B)

In the United States, the standard frequency of alternating current (AC) is 60 Hz. This means that the current alternates or cycles 60 times per second. The adoption of 60 Hz was largely influenced by historical decisions made during the development of electrical systems and equipment. Standardizing the frequency allows for compatibility in electrical devices, ensuring that they will operate effectively across the entire grid network. The choice of 60 Hz also aligns with the design of electrical generators and motors, which were optimized for this frequency based on factors like efficiency and performance. Additionally, using 60 Hz helps minimize power losses during transmission and keeps appliances and industrial equipment functioning reliably over extended periods. In contrast, the other frequencies listed—50 Hz, 70 Hz, and 100 Hz—are not used as standard in residential and commercial power distribution in the U.S. While 50 Hz is the standard frequency in many countries around the world, it does not apply to the U.S. grid. Frequencies like 70 Hz and 100 Hz are not commonly used for alternating current in any significant capacity in established systems.

In the United States, the standard frequency of alternating current (AC) is 60 Hz. This means that the current alternates or cycles 60 times per second. The adoption of 60 Hz was largely influenced by historical decisions made during the development of electrical systems and equipment. Standardizing the frequency allows for compatibility in electrical devices, ensuring that they will operate effectively across the entire grid network.

The choice of 60 Hz also aligns with the design of electrical generators and motors, which were optimized for this frequency based on factors like efficiency and performance. Additionally, using 60 Hz helps minimize power losses during transmission and keeps appliances and industrial equipment functioning reliably over extended periods.

In contrast, the other frequencies listed—50 Hz, 70 Hz, and 100 Hz—are not used as standard in residential and commercial power distribution in the U.S. While 50 Hz is the standard frequency in many countries around the world, it does not apply to the U.S. grid. Frequencies like 70 Hz and 100 Hz are not commonly used for alternating current in any significant capacity in established systems.