B=2rμ0 HI =(1)ϕB =NBAϕB =N(2rμ⋅NI )AϕB =(2μ⋅N2I )πr2ϕB =2μ⋅πN2Fγ−2 कण्..

B=2rμ0 HI =(1)ϕB =NBAϕB =N(2rμ⋅NI )AϕB =(2μ⋅N2I )πr2ϕB =2μ⋅πN2Fγ−2 कण्..