An a.c. source of frequency $f$ is connected to a circuit containing an inductance $L$ and resistance $R$ in series. The impedance of this circuit is

$A$ 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 ......$A$

An electric bulb has a rated power of $50 \, W$ at $100 \, V$. If it is used on an $AC$ source of $200 \, V, 50 \, Hz$, a choke has to be used in series with it. This choke should have an inductance of (in $ \, H$)

An alternating voltage is applied to a series $LCR$ circuit. If the current leads the voltage by $45^{\circ}$,then $\left(\tan 45^{\circ}=1\right)$:

An alternating emf given by the equation $E = 200 \sin(50 \pi t)$ (where $E$ is in volts and $t$ is in seconds) is applied across a series combination of an inductor and a resistor having inductive reactance $X_L = 40 \ \Omega$ and resistance $R = 30 \ \Omega$ respectively. At time $t = 1 \ s$,the power dissipated by the resistor is close to $(\cos 53^{\circ} = 0.6)$. (in $W$)

An e.m.f. $E = E_0 \cos \omega t$ is applied to an $L-R$ circuit. The inductive reactance is equal to the resistance $R$ of the circuit. The power consumed in the circuit is: