[填空题]
A long thin solenoid;rwcpxl/qd 5wk;b6 - h )z.c88,uzx(osr niwr has 430 loops of wire per meter, and a 25-A current flows through the wire. Iz,rs8)ui8rcn (x .wzof the permeability of the iron is $3000\mu_0$ what is the total field B inside the solenoid? T
