$Henry/ohm$ can be expressed in

Find the current in the $4 \Omega$ resistance shown in the figure in the following cases:
$(a)$ Just after the closing of the key.
$(b)$ $A$ long time after the closing of the key.

In the circuit shown,the final current through the $30\, \Omega$ resistance when the circuit is completed is ......... $A$.

An ideal coil of $10 \, H$ is joined in series with a resistance of $5 \, \Omega$ and a battery of $5 \, V$. $2 \, s$ after joining, the current flowing in the circuit in amperes will be:

The time constant of an inductance coil is $3 \text{ ms}$. When a $90 \Omega$ resistance is joined in series,the time constant becomes $0.5 \text{ ms}$. The inductance and the resistance of the coil are:

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 closed at time $t=0$. Find the initial $(t=0)$ and final $(t \rightarrow \infty)$ currents through the battery.