A light bulb and an inductor coil are connected to an ac source through a key as shown in the figure below. The key is closed and after sometime an iron rod is inserted into the interior of the inductor. The glow of the light bulb

A series LCR circuit (R = 30 Ω, $$\text X_\text L$$​ = 40 Ω, $$\text X_\text C$$​ = 80 Ω) is connected to an AC source of 200 V and 50 Hz. The power dissipated in the circuit is:

Consider a circuit with Resistance, Inductor and Capacitor connected in series. The phase difference between the current and the alternating voltage (at resonance) is: