What is the standard frequency for AC systems in the United States?

What is the standard frequency for AC systems in the United States?

• A. 120 mA
• B. 120 Hz
• C. 60 mA
• D. 60 Hz

Answer: (D)

In the United States, the standard frequency for alternating current (AC) systems is 60 Hz. This means that the AC power supply cycles 60 times per second. This frequency is established by the National Electrical Manufacturers Association (NEMA) as the standard for electrical systems in the U.S. Most electrical devices and appliances are designed to operate efficiently and effectively at this frequency. Understanding the frequency is essential because it impacts the operation of motors and transformers, as well as the overall efficiency and performance of electrical devices. Operating electrical equipment at the correct frequency ensures that they function properly and reduces the risk of damage that can occur when devices are run on a frequency for which they were not designed. While some other options mention values and units commonly associated with electrical systems, they do not represent the standard frequency in the U.S. For instance, milliamps (mA) are a unit of current measurement, not frequency, and the frequency of 120 Hz is not used in the U.S.—60 Hz is the established norm.

In the United States, the standard frequency for alternating current (AC) systems is 60 Hz. This means that the AC power supply cycles 60 times per second. This frequency is established by the National Electrical Manufacturers Association (NEMA) as the standard for electrical systems in the U.S. Most electrical devices and appliances are designed to operate efficiently and effectively at this frequency.

Understanding the frequency is essential because it impacts the operation of motors and transformers, as well as the overall efficiency and performance of electrical devices. Operating electrical equipment at the correct frequency ensures that they function properly and reduces the risk of damage that can occur when devices are run on a frequency for which they were not designed.

While some other options mention values and units commonly associated with electrical systems, they do not represent the standard frequency in the U.S. For instance, milliamps (mA) are a unit of current measurement, not frequency, and the frequency of 120 Hz is not used in the U.S.—60 Hz is the established norm.