What happens to the voltage across a coil when it is energized?

When a coil is energized, it experiences an increase in voltage to its rated level due to the applied current creating a magnetic field. This is foundational to how electromagnetic devices like relays and solenoids operate. Once the coil is connected to a voltage source, the inductance of the coil will determine how quickly it reaches this rated voltage. Initially, there may be a transient state where the voltage appears to rise due to the inrush current, but eventually, it stabilizes at the rated voltage as the magnetic field fully develops.

In essence, the coil functions as an inductor, and when energized, it will draw the required voltage to maintain the operation of the device for which it was designed. This is critical for the proper functioning of many motor control applications, where specific voltage levels are needed to ensure reliability and performance of the entire system.