$A$ coil has an inductance of $2 \ H$. The ratio of its reactance when it is connected first to an $A.C.$ source and then to a $D.C.$ source is:

$A$ $70 mH$ inductor is connected to a $220 V, 50 Hz$ $AC$ supply. The rms value of the current in the circuit is:

Let $f = 50\, Hz$ and $C = 100\, \mu F$ in an $AC$ circuit containing a capacitor only. If the peak value of the current in the circuit is $1.57\, A$,the expression for the instantaneous voltage across the capacitor will be (assuming current is $I = I_m \sin(\omega t)$):

Given below are two statements:
Statement-$I$: In an $AC$ circuit,the current through a capacitor leads the voltage across it.
Statement-$II$: In $AC$ circuits containing pure capacitance only,the phase difference between the current and the voltage is $\pi$.
In the light of the above statements,choose the most appropriate answer from the options given below:

An inductor is connected to an $AC$ source of frequency $50 \ Hz$. The frequency of the instantaneous power developed in the circuit is (in $Hz$)

The equation of current in a purely inductive circuit is $i = 5 \sin (49 \pi t - 30^{\circ})$. If the inductance is $30 \, mH$,then the equation for the voltage across the inductor will be. (Let $\pi = \frac{22}{7}$)