Answer:
1.77 x  [tex]10^{-7}[/tex]Wb
Explanation:
the magnitude of force given by one of the windings is given by "
   Ф = BA = ∪nIA
where B is the magnetic field strength inside the solenoid
   A is cross-sectiona area of the windings in [tex]m^{2}[/tex] = π x [tex]( \frac{0.75 x 10^{-2} }{2} )^{2}[/tex] = 4.418 x [tex]10^{-5}[/tex][tex]m^{2}[/tex]
      ∪ is the vacuum permeability = 4π x [tex]10^{-7}[/tex]H/m
      n i s given by n is number of turns per m = 160 x 100 per m = 16000/m
    Ф  = 4  x [tex]10^{-7}[/tex] x 3.142  x 16000 x  0.20 x 4.418 x [tex]10^{-5}[/tex] = 1.77 x  [tex]10^{-7}[/tex]  Wb
