A rod with circular cross-section area \(2c{m}^{2}\) and length 40cm is wound uniformly with 400 turns of an insulated w…

A rod with circular cross-section area \(2c{m}^{2}\) and length 40cm is wound uniformly with 400 turns of an insulated wire. If a current of 0.4A flows in the wire windings, the total magnetic flux produced inside windings is \(4\pi \times {10}^{-6}Wb\). The relative permeability of the rod is
(Given: Permeability of vacuum \({\mu }_{0}=4\pi \times {10}^{-7}N{A}^{-2}\) )

[JEE Main 2023, 31 Jan (Shift 1)]