A device 'X' is connected to an ac source V = V0 sin ωt. The variation of voltage, current and power in one cycle is shown in the following graph:
(a) Identify the device 'X'.
(b) Which of the curves A, B and C represent the voltage , current and the power consumed in the circuit? Justify your answer.
(c) How does its impedance vary with frequency of the ac source? Show graphically.
(d) Obtain an expression for the current in the circuit and its phase relation with ac voltage.