An $LR$ circuit with a battery is connected at $t = 0$. Which of the following quantities is not zero just after the circuit is closed?

An inductor coil carries a steady-state current of $2.0 \ A$ when connected across an ideal battery of $emf$ $4.0 \ V$. If its inductance is $1.0 \ H$,find the time constant of the circuit in $sec$.

An $L-R$ circuit has a cell of $e.m.f.$ $E$,which is switched on at time $t = 0$. The current in the circuit after a long time will be

$A$ coil of resistance $50 \Omega$ is connected across a $5.0 V$ battery. If the current in the coil is found to be $50 mA$ after the time $t=0.1 s$ of the battery being connected, then the inductance of the coil is:

Assertion : The resistance offered by an inductor in a $d.c.$ circuit is always constant.
Reason : The resistance of an inductor in a steady state is non-zero.

An inductor $(L = 0.03 \; H)$ and a resistor $(R = 0.15 \; k\Omega)$ are connected in series to a battery of $15 \; V$ $EMF$ in the circuit shown below. The key $K_1$ has been kept closed for a long time. Then at $t = 0$,$K_1$ is opened and key $K_2$ is closed simultaneously. At $t = 1 \; ms$,the current in the circuit will be ........... $mA$. $(e^5 \cong 150)$