$A$ resistance of $200 \ \Omega$ and an inductor of $\frac{1}{2 \pi} \ H$ are connected in series to an a.c. voltage of $40 \ V$ and $100 \ Hz$ frequency. The phase angle between the voltage and current is

The power factor of an $R-L$ circuit is $\frac{1}{\sqrt{2}}$. If the frequency of $AC$ is doubled,the power factor will now be

An alternating current source of frequency $100\, Hz$ is connected to a combination of a resistor,a capacitor,and an inductor in series. The potential difference across the inductor,the resistor,and the capacitor is $46\, V$,$8\, V$,and $40\, V$ respectively. The electromotive force $(EMF)$ of the alternating current source in volts is:

In an $AC$ circuit,a resistance of $R \, \Omega$ is connected in series with an inductance $L$. If the phase angle between voltage and current is $45^o$,the value of inductive reactance will be:

$A$ $220\, V$,$50\, Hz$ $ac$ source is connected to an inductance of $0.2\, H$ and a resistance of $20\, \Omega$ in series. What is the current in the circuit (in $, A$)?

An inductor of self-inductance $1 \ H$ is connected in series with a resistor of $100 \pi \ \Omega$ and an $AC$ supply of $100 \pi \ V$,$50 \ Hz$. The maximum current flowing in the circuit is . . . . . . $A$.