The following series $L-C-R$ circuit,when driven by an emf source of angular frequency $70 \text{ krad/s}$,behaves effectively as:

An e.m.f. $E = 4 \cos(1000t) \, V$ is applied to an $LR$-circuit of inductance $3 \, mH$ and resistance $4 \, \Omega$. The amplitude of current in the circuit is:

In a series $LCR$ circuit, the potential drop across $L, C$ and $R$ respectively are $40 \,V, 120 \,V$ and $60 \,V$. Then the source voltage is (in $\,V$)

$A$ sinusoidal voltage $V(t) = 210 \sin(3000t) \text{ V}$ is applied to a series $LCR$ circuit in which $L = 10 \text{ mH}$,$C = 25 \mu\text{F}$,and $R = 100 \Omega$. The phase difference $(\Phi)$ between the applied voltage and resultant current will be

When $80 \ V$ $d.c.$ is applied across a solenoid,a current of $0.8 \ A$ flows in it. When $80 \ V$ $a.c.$ is applied across the same solenoid,the current becomes $0.4 \ A$. If the frequency of $a.c.$ source is $50 \ Hz$,the impedance and inductance of the solenoid are nearly:

$A$ coil has resistance $30\,\Omega$ and inductive reactance $20\,\Omega$ at $50\,Hz$ frequency. If an $AC$ source of $200\,V, 100\,Hz$ is connected across the coil,the current in the coil will be ......$A$