A current of 5A exists in a square loop of side $\frac{1}{{\sqrt 2 }}\;{\rm{m}}$ . Then the magnitude of the magnetic field B at the centre of the square loop will be $p \times {10^{ - 6}}\;{\rm{T}}$. where, value of p is ________ [Take ${\mu _0} = 4\pi \times {10^{ - 7}}\;{\rm{T}}\;{\rm{m}}{{\rm{A}}^{ - 1}}$].