Alternating Cur...

From the figure shown, a series L-C-R circuit connected to a variable frequency $$200\, V$$ source. $$L=5H,\, C=80\, \mu F$$ and $$R=40 \Omega$$. Then the source frequency which drives the circuit at resonance is

In a series LCR circuit K = 200 S2 and the voltage and frequency of the main supply are 220 V and 50 Hz respectively. On taking out the capacitor from the circuit, the current leads the voltage by 30. On taking out the indicator from the circuit the current leads the voltage by 30. The power dissipated in the LCR circuit is :

In an AC circuit instantaneous current is given by $$i=i_0sin\dfrac{\pi}{6}t.$$ The time from starting when current in circuit becomes equal to its rms value for the first time is 

The power factor of a circuit in which a box having unknown electrical devices connected in series with a resistor of resistance $$3\Omega$$ is $$3/5$$. The reactance  of the box is

A potential difference of $$6V$$ is applied to a coil of inductance $$0.5\ H$$ and a resistance of $$4\ ohm$$ connected in series. The time taken for the current to reach half is maximum value is (in seconds).

In a series resonant LCR circuit, the voltage across $$ R  $$ is 100$$  V  $$ and $$  R= $$ 1$$  k \Omega  $$ with $$  C $$ $$ =2 \mu F . \operatorname{The} $$ resonant frequency $$  \omega  $$ is 200 $$ \mathrm{rad} / \mathrm{s}  $$ . At resonance the voltage across L is:

Growth of current in two different L-R circuit are depicted by the I-t graphs shown. Angle subtended by the curves with time axis at time t=0 are also shown in the graph $${ \tau  }_{ 1 }$$ and $${ \tau  }_{ 2 }$$ are time constants for the circuits 1 and 2 respectively. Choose the CORRECT alternative

Which of the following combinations should be selected for better tunning of an $$LCR$$ circuit used for communication

The equation of an alternating voltage is $$V = 220\sin \left [\omega t + \dfrac {\pi}{6}\right ]$$ and the equation for current is $$I = 10\sin \left (\omega t + \dfrac {\pi}{6}\right )$$. The impedance (in ohm) of the circuit is

Find the resonant frequency and $$Q-factor$$ of a series $$LCR$$ circuit with $$L = 3.0\ H, C = 27\mu F$$ and $$R = 7.4\Omega$$.