What is one effect of alternating current's frequency on a motor?

In the context of motors, alternating current frequency plays a crucial role in determining the speed at which the motor operates. This is particularly evident in synchronous motors, where the synchronous speed is directly tied to the frequency of the input AC power supply. The relationship can be expressed with the formula:

[ \text{Synchronous Speed (RPM)} = \frac{120 \times \text{Frequency (Hz)}}{\text{Number of Poles}} ]

As the frequency increases, the synchronous speed of the motor also increases, resulting in a faster operating speed. Conversely, if the frequency decreases, the synchronous speed will also drop, leading to a slower motor speed. This critical relationship highlights how varying the AC frequency directly influences the motor's operational speed, making it a fundamental aspect of motor control and operation.