An ac source is connected to a capacitor C. Due to decrease in its operating frequency

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: