A light bulb and an open coil inductor are connected to an ac source through a key as shown in Figure

The switch is closed and after sometime, an iron rod is inserted into the interior of the inductor. The glow of the light bulb $(a)$ increases; $(b)$ decreases; $(c)$ is unchanged, as the iron rod is inserted. Give your answer with reasons

Two resistors of $10\, \Omega$ and $20\, \Omega$ and an ideal inductor of $10\, H$ are connected to a $2\, V$ battery as shown. The key $K$ is inserted at time $t = 0$. The initial $(t = 0)$ and final ($t \rightarrow \infty$ ) currents through battery are

When an ac generator of $120\,V$ is connected in series with a capacitor and a resistor of $30\,\Omega $, the circuit carries a current $1·5\,A$. The potential difference across the capacitor will be…..$V$

In the circuit shown, The switch $S_1$ is close at time $t = 0$ and the switch $S_2$ is kept open. At some later time $(t_0)$ the switch $S_1$ is opened and $S_2$ is closed. The behaviour of the current $I$ as a function of time $‘t’$ is given by

A $100 \;\mu\,F$ capacitor in series with a $40\; \Omega$ resistance is connected to a $110\; V , 60\; Hz$ supply.

$(a)$ What is the maximum current in the circuit?

$(b)$ What is the time lag between the current maximum and the voltage maximum?