question_answer

An alternating e.m.f. of frequency \[v\,\left( =\frac{1}{2\pi \sqrt{LC}} \right)\] is applied to a series LCR circuit. For this frequency of the applied e.m.f.                                                                [Roorkee 1999]

A)            The circuit is at resonance and its impedance is made up only of a reactive part

B)            The current in the circuit is in phase with the applied e.m.f. and the voltage across R equals this applied emf

C)            The sum of the p.d.?s across the inductance and capacitance equals the applied e.m.f. which is \[{{180}^{o}}\] ahead of phase of the current in the circuit

D)            The quality factor of the circuit is \[\omega L/R\] or \[1/\omega CR\] and this is a measure of the voltage magnification (produced by the circuit at resonance) as well as the sharpness of resonance of the circuit