What is the effect of inserting any ferromagnetic, diamagnetic etc in magnetic field?? let me say there is a solenoid of turns per unit length n.magnetic field inside the solenoid will ~μnI. what will happen if an ferromagnetic substance like iron is inserted. How will it effect the magnetic field inside the solenoid. I think like dielectrics it should also affect the value of μ But how will it effect it? similarly how diamagnetic substances will change the scene..??? thanks for replying..