How much time does it take for the current to decay to half of its initial value in the following charging circuit?

After closing the key in the given circuit:
$(a)$ Bulb $(2)$ will glow and maintain its brightness.
$(b)$ Brightness of bulb $(1)$ will gradually decrease and at steady state it goes completely dark.

In the circuit shown in the figure,what happens in the steady state?

In the $RC$ circuit shown,the switch is closed at $t = 0$. Graphs showing the variation of potential $(V_R)$ across the resistor and potential $(V_C)$ across the capacitor are given. The time constant of the circuit is approximately equal to.....$ms$

In the given figure,initially the capacitor is uncharged. The ratio of current at $t = 0$ and $t = \infty$ will be:

$A$ charged capacitor is allowed to discharge through a resistance of $2 \, \Omega$ by closing the switch $S$ at the instant $t = 0$. At time $t = \ln 2 \, \mu s$,the reading of the ammeter falls to half of its initial value. The resistance of the ammeter is equal to: