An air core solenoid has $1000$ turns and is one metre long. Its cross-sectional area is $10 \, cm^2$. Its self-inductance is: (in $, mH$)

If $N$ is the number of turns in a coil,the value of self-inductance varies as

This question has Statement $1$ and Statement $2.$ Of the four choices given after the Statements,choose the one that best describes the two Statements.
Statement $1 :$ Self inductance of a long solenoid of length $L,$ total number of turns $N$ and radius $r$ is less than $\frac{{\pi {\mu _0}{N^2}{r^2}}}{L}$
Statement $2:$ The magnetic induction in the solenoid in Statement $1$ carrying current $I$ is $\frac{{{\mu _0}NI}}{L}$ in the middle of the solenoid but becomes less as we move towards its ends.

The current flowing through an inductance coil of self-inductance $6 \text{ mH}$ at different time instants is as shown. The emf induced between $t=20 \text{ s}$ and $t=40 \text{ s}$ is nearly

$A$ solenoid has a length of $1 \,m$ and a cross-sectional area of $0.02 \,m^2$. If the number of turns in the solenoid is $5000$, then the self-inductance of the solenoid is: (in $\pi \,H$)

The self-inductance of a straight conductor is