Draw a labelled diagram of an ac generator. Write the principle on which it works.

Derive an expression for the average power consumed in a series LCR circuit connected to ac source in which the phase-difference between the voltage and current in the circuit is $\varphi$

A series LCR circuit is connected to an ac source having voltage $v=v_m\sin \omega t$. Derive the expression for the instantaneous current $I$ and the phase relationship to the applied voltage. Obtain the condition for resonance to occur. Define power factor. State the conditions under which it is

(i) Maximum,

A series LCR circuit is connected to an ac source having voltage $v=v_m\sin \omega t$. Derive the expression for the instantaneous current $I$ and the phase relationship to the applied voltage. Obtain the condition for resonance to occur. Define power factor. State the conditions under which it is

(ii) Minimum.