List of top Physics Questions on AC Voltage Applied to a Series LCR Circuit

An AC voltage \[ V=220\sin(2\times10^{3}t)\ \text{Volt} \] is applied to a series LCR circuit. Then the current amplitude in the circuit is: Given: \[ L=10\,\text{mH},\quad C=25\,\mu\text{F},\quad R=100\,\Omega \]

(i) A series combination of L, C and R is connected to an ac source \(V = V_m \sin \omega t\). Obtain:

(I) the impedance of the circuit using phasor diagram,

(II) the expression for the instantaneous current I, and

(III) the phase relationship of current to the applied voltage.

(ii) Define power factor of an ac circuit. State the conditions under which it is: (I) maximum, (II) minimum.

An inductor of 500 mH is in series with a resistance and a variable capacitor connected to a source of frequency 0.4 kHz. The value of capacitance of the capacitor to get a maximum current will be