# What happens when an inductor is connected to AC mains ?

When an inductor is connected to AC mains, it responds to the alternating current by generating a magnetic field that opposes changes in the current flow. Due to the inductor’s property of inductance, it resists sudden changes in current by inducing a voltage (back EMF) opposite to the direction of the current. This results in a phase shift where the current lags behind the voltage. The impedance of the inductor increases with the frequency of the AC signal, which affects the overall current flow through the circuit.

When AC supply is given to an inductor, the inductor creates a magnetic field around itself that fluctuates with the changing current. This changing magnetic field induces an electromotive force (EMF) that opposes the change in current, as described by Lenz’s Law. The inductor resists the initial change in current, causing the current to rise gradually instead of instantaneously. The current through the inductor will reach its maximum value after a certain period, lagging behind the applied voltage.

In an AC circuit, an inductor primarily acts to oppose changes in current. This opposition is due to the inductance, which causes a phase shift between the voltage and the current. The voltage across the inductor leads the current by 90 degrees, meaning the current lags behind the voltage. This property is exploited in applications like filtering, tuning, and controlling the phase of AC signals. The inductor’s impedance, which is a combination of resistance and inductive reactance, increases with frequency, making it useful in frequency-selective circuits.

When an inductor is connected to an AC source, it behaves as a reactive component that resists changes in current. The inductor generates a back EMF in response to the alternating current, which causes the current to lag behind the voltage. The impedance of the inductor, given by Z=jωLZ = j\omega LZ=jωL (where ω\omegaω is the angular frequency and LLL is the inductance), increases with the frequency of the AC source. This results in a lower current at higher frequencies, making inductors effective for filtering high-frequency signals.

When AC current flows through an inductor, the inductor generates a time-varying magnetic field that induces a voltage opposing the change in current. This effect causes the current to lag behind the voltage by 90 degrees in an ideal inductor. The alternating current causes the magnetic field to continually build up and collapse, creating a reactive opposition to the current known as inductive reactance. This inductive reactance increases with the frequency of the AC current, reducing the amplitude of the current that can pass through the inductor at higher frequencies.