What happens to the strength of the magnetic field around a coil when AC voltage is applied?

When alternating current (AC) voltage is applied to a coil, the magnetic field produced around the coil exhibits a phenomenon known as varying magnetic field strength. This occurs because AC voltage causes the current within the coil to change direction periodically.

As the AC voltage alternates, the current also alternates between positive and negative values, leading to fluctuations in the flow of electric charge. These changes in current create a magnetic field that continuously fluctuates in strength and direction. Thus, the strength of the magnetic field does not remain constant; rather, it varies in response to the oscillating nature of the AC voltage.

This concept is fundamental in understanding how inductors and transformers operate within AC circuits, as the changing magnetic field plays a crucial role in their functionality.