a. Draw graphs showing the variations of inductive reactance and capacitive reactance with frequency of applied ac source. b. Draw the phasor diagram for a series LRC circuit connected to an AC source. c. When an alternating voltage of 220V is applied across a device X, a current of 0.25A flows which lags behind the applied voltage in phase by π/2 radian. If the same voltage is applied across another device Y, the same current flows but now it is in phase with the applied voltage. (i) Name the devices X and Y. (ii) Calculate the current flowing in the circuit when the same voltage is applied across the series combination of X and Y.
OR
a. A series LCR circuit is connected to an ac source. Using the phasor diagram, derive the expression for the impedance of the circuit. b. Plot a graph to show the variation of current with frequency of the ac source , explaining the nature of its variation for two different resistances R1 and R2 (R1< R2) at resonance.
