Step 1: Use the formula for self inductance of a solenoid.
The self inductance of a long solenoid is given by
\[
L=\frac{\mu_0N^2A}{l}
\]
where
\[
\mu_0=4\pi\times10^{-7}\ \text{H m}^{-1},
\]
\[
N=5000,
\]
\[
A=0.02\ \text{m}^2,
\]
\[
l=1\ \text{m}.
\]
Step 2: Substitute the given values.
\[
L
=
\frac{(4\pi\times10^{-7})(5000)^2(0.02)}{1}
\]
Since
\[
(5000)^2
=
25\times10^6,
\]
we get
\[
L
=
(4\pi\times10^{-7})
(25\times10^6)
(0.02)
\]
Step 3: Simplify the numerical part.
\[
25\times0.02
=
0.5
\]
Therefore,
\[
L
=
4\pi\times10^{-7}\times0.5\times10^6
\]
\[
L
=
2\pi\times10^{-1}
\]
\[
L
=
0.2\pi\ \text{H}
\]
Step 4: Final conclusion.
Hence, the self inductance of the solenoid is
\[
\boxed{0.2\pi\ \text{henry}}
\]