AC Voltage Applied to an Inductor An alternating current (AC) voltage applied to an inductor causes the current within the coil to periodically change di...
An alternating current (AC) voltage applied to an inductor causes the current within the coil to periodically change direction. This induces an electromotive force (EMF) in the coil, which causes the voltage across the coil to vary sinusoidally.
An inductor is an electrical component that stores energy by inducing an EMF in a conductor when an alternating current is passed through it. Inductors are commonly used in circuits to filter AC signals, as they can block DC components while allowing AC components to pass through.
Key points:
An AC voltage applied to an inductor causes the current to oscillate between two directions.
This oscillating current induces an EMF in the coil, which in turn causes the voltage across the coil to vary sinusoidally.
The frequency of the AC voltage determines the frequency of the current oscillations.
An inductor opposes changes in current, which means that the voltage across the coil is constant regardless of the current direction.
Example:
Consider an AC voltage source with a frequency of 50 Hz. If the voltage is applied across an inductor with a resistance of 10 Ω, the induced EMF will have a frequency of 50 Hz. This means that the voltage across the coil will oscillate between 0 V and 1 V with a period of 100 ms.
Additional notes:
The magnitude of the induced EMF is proportional to the strength of the AC voltage and the inductance of the coil.
The voltage across an inductor is always negative during the first half-cycle of the current oscillations.
The power delivered by the AC voltage to the inductor is equal to the square of the current amplitude